Fix documented type for entry point function (#147)

Author: mkroening

src/boot_info.rs

@@ -8,7 +8,7 @@ use core::{ops, slice};
 /// ```
 /// # use bootloader::BootInfo;
 /// # type _SIGNATURE =
-/// extern "C" fn(boot_info: &'static BootInfo) -> !;
+/// extern "C" fn(boot_info: &'static mut BootInfo) -> !;
 /// ```
 ///
 /// Note that no type checking occurs for the entry point function, so be careful to

src/lib.rs

@@ -104,7 +104,7 @@ compile_error!("This crate only supports the x86_64 architecture.");
 
 /// Defines the entry point function.
 ///
-/// The function must have the signature `fn(&'static BootInfo) -> !`.
+/// The function must have the signature `fn(&'static mut BootInfo) -> !`.
 ///
 /// This macro just creates a function named `_start`, which the linker will use as the entry
 /// point. The advantage of using this macro instead of providing an own `_start` function is