Fix clippy::uninlined_format_args warning

```
error: variables can be used directly in the `format!` string
  --> examples/linux-inotify.rs:55:17
   |
55 |                 println!("{:?}", event);
   |                 ^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
   = note: `-D clippy::uninlined-format-args` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::uninlined_format_args)]`
help: change this to
   |
55 -                 println!("{:?}", event);
55 +                 println!("{event:?}");
   |

error: variables can be used directly in the `format!` string
  --> benches/io.rs:35:30
   |
35 |         group.bench_function(format!("TcpStream.{}", driver_name), move |b| {
   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
   = note: `-D clippy::uninlined-format-args` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::uninlined_format_args)]`
help: change this to
   |
35 -         group.bench_function(format!("TcpStream.{}", driver_name), move |b| {
35 +         group.bench_function(format!("TcpStream.{driver_name}"), move |b| {
   |

error: variables can be used directly in the `format!` string
  --> benches/io.rs:58:34
   |
58 |             group.bench_function(format!("UnixStream.{}", driver_name), |b| {
   |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
help: change this to
   |
58 -             group.bench_function(format!("UnixStream.{}", driver_name), |b| {
58 +             group.bench_function(format!("UnixStream.{driver_name}"), |b| {
   |

error: variables can be used directly in the `format!` string
  --> benches/io.rs:82:30
   |
82 |         group.bench_function(format!("TcpStream.{}", driver_name), move |b| {
   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
help: change this to
   |
82 -         group.bench_function(format!("TcpStream.{}", driver_name), move |b| {
82 +         group.bench_function(format!("TcpStream.{driver_name}"), move |b| {
   |

error: variables can be used directly in the `format!` string
   --> benches/io.rs:108:31
    |
108 |             let socket_addr = format!("/tmp/async-io-bench-{}.sock", id);
    |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
help: change this to
    |
108 -             let socket_addr = format!("/tmp/async-io-bench-{}.sock", id);
108 +             let socket_addr = format!("/tmp/async-io-bench-{id}.sock");
    |

error: variables can be used directly in the `format!` string
   --> benches/io.rs:111:34
    |
111 |             group.bench_function(format!("UnixStream.{}", driver_name), |b| {
    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
help: change this to
    |
111 -             group.bench_function(format!("UnixStream.{}", driver_name), |b| {
111 +             group.bench_function(format!("UnixStream.{driver_name}"), |b| {
    |

error: variables can be used directly in the `format!` string
   --> benches/io.rs:145:30
    |
145 |         group.bench_function(format!("UdpSocket.{}", driver_name), |b| {
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
help: change this to
    |
145 -         group.bench_function(format!("UdpSocket.{}", driver_name), |b| {
145 +         group.bench_function(format!("UdpSocket.{driver_name}"), |b| {
    |

error: variables can be used directly in the `format!` string
  --> benches/timer.rs:27:13
   |
27 |             format!("register_timer.({} previous timers)", prev_timer_count),
   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
   = note: `-D clippy::uninlined-format-args` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::uninlined_format_args)]`
help: change this to
   |
27 -             format!("register_timer.({} previous timers)", prev_timer_count),
27 +             format!("register_timer.({prev_timer_count} previous timers)"),
   |
```

Author: taiki-e

benches/io.rs

@@ -32,7 +32,7 @@ fn read_and_write(b: &mut Criterion) {
             (listener, reader, writer)
         };
 
-        group.bench_function(format!("TcpStream.{}", driver_name), move |b| {
+        group.bench_function(format!("TcpStream.{driver_name}"), move |b| {
             let (_listener, mut reader, mut writer) = init_reader_writer();
             let mut buf = vec![0x42; TCP_AMOUNT];
 
@@ -55,7 +55,7 @@ fn read_and_write(b: &mut Criterion) {
             use std::os::unix::net::UnixStream;
             const UNIX_AMOUNT: usize = 1024;
 
-            group.bench_function(format!("UnixStream.{}", driver_name), |b| {
+            group.bench_function(format!("UnixStream.{driver_name}"), |b| {
                 let (mut reader, mut writer) = Async::<UnixStream>::pair().unwrap();
                 let mut buf = vec![0x42; UNIX_AMOUNT];
 
@@ -79,7 +79,7 @@ fn connect_and_accept(c: &mut Criterion) {
 
     for (driver_name, exec) in [("Undriven", false), ("Driven", true)] {
         // Benchmark the TCP streams.
-        group.bench_function(format!("TcpStream.{}", driver_name), move |b| {
+        group.bench_function(format!("TcpStream.{driver_name}"), move |b| {
             let socket_addr =
                 SocketAddr::new("127.0.0.1".parse::<Ipv4Addr>().unwrap().into(), 12345);
             let listener = Async::<TcpListener>::bind(socket_addr).unwrap();
@@ -105,10 +105,10 @@ fn connect_and_accept(c: &mut Criterion) {
             getrandom::fill(&mut id).unwrap();
             let id = u64::from_ne_bytes(id);
 
-            let socket_addr = format!("/tmp/async-io-bench-{}.sock", id);
+            let socket_addr = format!("/tmp/async-io-bench-{id}.sock");
             let listener = Async::<UnixListener>::bind(&socket_addr).unwrap();
 
-            group.bench_function(format!("UnixStream.{}", driver_name), |b| {
+            group.bench_function(format!("UnixStream.{driver_name}"), |b| {
                 b.iter(|| {
                     block_on(
                         async {
@@ -142,7 +142,7 @@ fn udp_send_recv(c: &mut Criterion) {
     let mut buf = vec![0x42; UDP_AMOUNT];
 
     for (driver_name, exec) in [("Undriven", false), ("Driven", true)] {
-        group.bench_function(format!("UdpSocket.{}", driver_name), |b| {
+        group.bench_function(format!("UdpSocket.{driver_name}"), |b| {
             b.iter(|| {
                 let buf = &mut buf;
 

benches/timer.rs

@@ -24,7 +24,7 @@ fn register_timer(c: &mut Criterion) {
 
         // Benchmark registering a timer.
         group.bench_function(
-            format!("register_timer.({} previous timers)", prev_timer_count),
+            format!("register_timer.({prev_timer_count} previous timers)"),
             |b| {
                 b.iter(|| {
                     let timer = make_timer();

examples/linux-inotify.rs

@@ -52,7 +52,7 @@ fn main() -> std::io::Result<()> {
         // Wait for events in a loop and print them on the screen.
         loop {
             for event in unsafe { inotify.read_with_mut(read_op).await? } {
-                println!("{:?}", event);
+                println!("{event:?}");
             }
         }
     })