chore: clippy and doc fixes (#6081)

tokio-util/src/sync/cancellation_token.rs

@@ -133,7 +133,7 @@ impl Default for CancellationToken {
 }
 
 impl CancellationToken {
-    /// Creates a new CancellationToken in the non-cancelled state.
+    /// Creates a new `CancellationToken` in the non-cancelled state.
     pub fn new() -> CancellationToken {
         CancellationToken {
             inner: Arc::new(tree_node::TreeNode::new()),

tokio-util/src/sync/cancellation_token/tree_node.rs

@@ -1,12 +1,12 @@
 //! This mod provides the logic for the inner tree structure of the CancellationToken.
 //!
-//! CancellationTokens are only light handles with references to TreeNode.
-//! All the logic is actually implemented in the TreeNode.
+//! CancellationTokens are only light handles with references to [`TreeNode`].
+//! All the logic is actually implemented in the [`TreeNode`].
 //!
-//! A TreeNode is part of the cancellation tree and may have one parent and an arbitrary number of
+//! A [`TreeNode`] is part of the cancellation tree and may have one parent and an arbitrary number of
 //! children.
 //!
-//! A TreeNode can receive the request to perform a cancellation through a CancellationToken.
+//! A [`TreeNode`] can receive the request to perform a cancellation through a CancellationToken.
 //! This cancellation request will cancel the node and all of its descendants.
 //!
 //! As soon as a node cannot get cancelled any more (because it was already cancelled or it has no

tokio-util/src/sync/poll_semaphore.rs

@@ -29,7 +29,7 @@ impl PollSemaphore {
 
     /// Closes the semaphore.
     pub fn close(&self) {
-        self.semaphore.close()
+        self.semaphore.close();
     }
 
     /// Obtain a clone of the inner semaphore.