library: Normalize safety-for-unsafe-block comments

Almost all safety comments are of the form `// SAFETY:`,
so normalize the rest and fix a few of them that should
have been a `/// # Safety` section instead.

Furthermore, make `tidy` only allow the uppercase form. While
currently `tidy` only checks `core`, it is a good idea to prevent
`core` from drifting to non-uppercase comments, so that later
we can start checking `alloc` etc. too.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/library/std/src/sys_common/rwlock.rs b/library/std/src/sys_common/rwlock.rs
index 41e8ad77294..70b31b19f82 100644
--- a/library/std/src/sys_common/rwlock.rs
+++ b/library/std/src/sys_common/rwlock.rs
@@ -103,7 +103,7 @@ impl StaticRWLock {
     /// The lock is automatically unlocked when the returned guard is dropped.
     #[inline]
     pub fn read_with_guard(&'static self) -> RWLockReadGuard {
-        // Safety: All methods require static references, therefore self
+        // SAFETY: All methods require static references, therefore self
         // cannot be moved between invocations.
         unsafe {
             self.0.read();
@@ -117,7 +117,7 @@ impl StaticRWLock {
     /// The lock is automatically unlocked when the returned guard is dropped.
     #[inline]
     pub fn write_with_guard(&'static self) -> RWLockWriteGuard {
-        // Safety: All methods require static references, therefore self
+        // SAFETY: All methods require static references, therefore self
         // cannot be moved between invocations.
         unsafe {
             self.0.write();