virtio-devices: vhost_user: fs: Don't reference packed struct

error: reference to packed field is unaligned
  --> virtio-devices/src/vhost_user/fs.rs:85:21
   |
85 |                     fs.flags[i].bits() as i32,
   |                     ^^^^^^^^^^^
   |
   = note: `-D unaligned-references` implied by `-D warnings`
   = warning: this was previously accepted by the compiler but is being
phased out; it will become a hard error in a future release!
   = note: for more information, see issue #82523
<rust-lang/rust#82523>
   = note: fields of packed structs are not properly aligned, and
creating a misaligned reference is undefined behavior (even if that
reference is never dereferenced)

Signed-off-by: Rob Bradford <[email protected]>

Author: rbradford

virtio-devices/src/vhost_user/fs.rs

@@ -78,11 +78,12 @@ impl VhostUserMasterReqHandler for SlaveReqHandler {
             }
 
             let addr = self.mmap_cache_addr + offset;
+            let flags = fs.flags[i];
             let ret = unsafe {
                 libc::mmap(
                     addr as *mut libc::c_void,
                     len as usize,
-                    fs.flags[i].bits() as i32,
+                    flags.bits() as i32,
                     libc::MAP_SHARED | libc::MAP_FIXED,
                     fd,
                     fs.fd_offset[i] as libc::off_t,