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/alloc/src/collections/btree/map/entry.rs b/library/alloc/src/collections/btree/map/entry.rs
index 6cc8813bc52..941f82a8070 100644
--- a/library/alloc/src/collections/btree/map/entry.rs
+++ b/library/alloc/src/collections/btree/map/entry.rs
@@ -278,14 +278,14 @@ impl<'a, K: Ord, V> VacantEntry<'a, K, V> {
     pub fn insert(self, value: V) -> &'a mut V {
         let out_ptr = match self.handle.insert_recursing(self.key, value) {
             (Fit(_), val_ptr) => {
-                // Safety: We have consumed self.handle and the handle returned.
+                // SAFETY: We have consumed self.handle and the handle returned.
                 let map = unsafe { self.dormant_map.awaken() };
                 map.length += 1;
                 val_ptr
             }
             (Split(ins), val_ptr) => {
                 drop(ins.left);
-                // Safety: We have consumed self.handle and the reference returned.
+                // SAFETY: We have consumed self.handle and the reference returned.
                 let map = unsafe { self.dormant_map.awaken() };
                 let root = map.root.as_mut().unwrap();
                 root.push_internal_level().push(ins.kv.0, ins.kv.1, ins.right);