rust: pin-init: use Markdown autolinks in Rust comments

"Normal" comments in Rust (`//`) are also formatted in Markdown, like
the documentation (`///` and `//!`), see
Documentation/rust/coding-guidelines.rst

Thus use Markdown autolinks for a couple links that were missing it.

It also helps to get proper linking in some software like kitty [1].

Suggested-by: Benno Lossin <benno.lossin@proton.me>
Link: Rust-for-Linux/pin-init#32 (comment) [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Link: Rust-for-Linux/pin-init@dd230d6
Fixes: 84837cf ("rust: pin-init: change examples to the user-space version")
Cc: stable@vger.kernel.org
[ Change case in title. Reworded commit message. - Benno ]
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20250407201755.649153-3-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

rust/pin-init/examples/pthread_mutex.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: Apache-2.0 OR MIT
 
-// inspired by https://github.com/nbdd0121/pin-init/blob/trunk/examples/pthread_mutex.rs
+// inspired by <https://github.com/nbdd0121/pin-init/blob/trunk/examples/pthread_mutex.rs>
 #![allow(clippy::undocumented_unsafe_blocks)]
 #![cfg_attr(feature = "alloc", feature(allocator_api))]
 #[cfg(not(windows))]

rust/pin-init/src/lib.rs

@@ -1447,7 +1447,7 @@ impl_zeroable! {
     {<T: ?Sized + Zeroable>} UnsafeCell<T>,
 
     // SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee:
-    // https://doc.rust-lang.org/stable/std/option/index.html#representation).
+    // <https://doc.rust-lang.org/stable/std/option/index.html#representation>).
     Option<NonZeroU8>, Option<NonZeroU16>, Option<NonZeroU32>, Option<NonZeroU64>,
     Option<NonZeroU128>, Option<NonZeroUsize>,
     Option<NonZeroI8>, Option<NonZeroI16>, Option<NonZeroI32>, Option<NonZeroI64>,