rust: kernel: fix multiple typos in documentation

Fixes multiple trivial typos in documentation and comments of the
kernel crate.

allocator:
- Fix a trivial list item alignment issue in the last SAFETY comment of
  `krealloc_aligned`.

init:
- Replace 'type' with 'trait' in the doc comments of the `PinInit` and
  `Init` traits.
- Add colons before starting lists.
- Add spaces between the type and equal sign to respect the code
  formatting rules in example code.
- End a sentence with a full stop instead of a colon.

ioctl:
- Replace 'an' with 'a' where appropriate.

str:
- Replace 'Return' with 'Returns' in the doc comment of `bytes_written`
  as the text describes what the function does.

sync/lock:
- Fix a trivial list item alignment issue in the Safety section of the
  `Backend` trait's description.

sync/lock/spinlock:
- The code in this module operates on spinlocks, not mutexes. Thus,
  replace 'mutex' with 'spinlock' in the SAFETY comment of `unlock`.

workqueue:
- Replace "wont" with "won't" in the doc comment of `__enqueue`.

Signed-off-by: Valentin Obst <kernel@valentinobst.de>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-1-0c8af94ed7de@valentinobst.de
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust/kernel/sync/lock.rs

@@ -21,9 +21,9 @@ pub mod spinlock;
 /// # Safety
 ///
 /// - Implementers must ensure that only one thread/CPU may access the protected data once the lock
-/// is owned, that is, between calls to `lock` and `unlock`.
+///   is owned, that is, between calls to `lock` and `unlock`.
 /// - Implementers must also ensure that `relock` uses the same locking method as the original
-/// lock operation.
+///   lock operation.
 pub unsafe trait Backend {
     /// The state required by the lock.
     type State;

rust/kernel/sync/lock/spinlock.rs

@@ -112,7 +112,7 @@ unsafe impl super::Backend for SpinLockBackend {
 
     unsafe fn unlock(ptr: *mut Self::State, _guard_state: &Self::GuardState) {
         // SAFETY: The safety requirements of this function ensure that `ptr` is valid and that the
-        // caller is the owner of the mutex.
+        // caller is the owner of the spinlock.
         unsafe { bindings::spin_unlock(ptr) }
     }
 }