rust: rbtree: fix `SAFETY` comments that should be `# Safety` sections

The tag `SAFETY` is used for safety comments, i.e. `// SAFETY`, while a
`Safety` section is used for safety preconditions in code documentation,
i.e. `/// # Safety`.

Fix the three instances recently added in `rbtree` that Clippy would
have normally caught in a public item, so that we can enable checking
of private items in one of the following commits.

Fixes: 98c14e40e07a ("rust: rbtree: add cursor")
Reviewed-by: Trevor Gross <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Tested-by: Gary Guo <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

0 files changed, 0 insertions, 0 deletions