sync: fix spelling mistake in mpsc::Sender docs
@@ -887,7 +887,7 @@ impl<T> Sender<T> {
/// let permit = tx.reserve().await.unwrap();
/// assert_eq!(tx.capacity(), 4);
///
- /// // Sending and receiving a value increases the caapcity by one.
+ /// // Sending and receiving a value increases the capacity by one.
/// permit.send(());
/// rx.recv().await.unwrap();
/// assert_eq!(tx.capacity(), 5);
