docs(rust): use Markdown autolinks in plain URL comments

Fixes #1153 – some comments in Rust files were using plain URLs instead of
Markdown autolink syntax. This change updates them to use proper autolinks
for consistency and improved rendering in documentation tools.

Link: #1153

Signed-off-by: Abhishek Brahmbhatt <[email protected]>

Author: brambhattabhishek

rust/kernel/alloc/kbox.rs

@@ -101,7 +101,7 @@ pub type VBox<T> = Box<T, super::allocator::Vmalloc>;
 pub type KVBox<T> = Box<T, super::allocator::KVmalloc>;
 
 // 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>).
 unsafe impl<T, A: Allocator> ZeroableOption for Box<T, A> {}
 
 // SAFETY: `Box` is `Send` if `T` is `Send` because the `Box` owns a `T`.

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>,