sync: reword allocation failure paragraph in broadcast docs (#7595)

tokio/src/sync/broadcast.rs

@@ -503,7 +503,7 @@ const MAX_RECEIVERS: usize = usize::MAX >> 2;
 /// This will panic if `capacity` is equal to `0`.
 ///
 /// This pre-allocates space for `capacity` messages. Allocation failure may result in a panic or
-/// [an allocation failure](std::alloc::handle_alloc_error).
+/// [an allocation error](std::alloc::handle_alloc_error).
 #[track_caller]
 pub fn channel<T: Clone>(capacity: usize) -> (Sender<T>, Receiver<T>) {
     // SAFETY: In the line below we are creating one extra receiver, so there will be 1 in total.