rust: error: Markdown style nit

This patch fixes a trivial markdown style nit in the `SAFETY` comment.

Signed-off-by: Manmohan Shukla <manmshuk@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Jianguo Bao <roidinev@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Fixes: c7e20faa5fca ("rust: error: Add Error::to_ptr()")
Link: https://lore.kernel.org/r/20230906204857.85619-1-manmshuk@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 0f29e7b..032b645 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -133,7 +133,7 @@ pub fn to_errno(self) -> core::ffi::c_int {
     /// Returns the error encoded as a pointer.
     #[allow(dead_code)]
     pub(crate) fn to_ptr<T>(self) -> *mut T {
-        // SAFETY: self.0 is a valid error due to its invariant.
+        // SAFETY: `self.0` is a valid error due to its invariant.
         unsafe { bindings::ERR_PTR(self.0.into()) as *mut _ }
     }