Fix WebSocketUpgrade::write_buffer_size docs

axum/src/extract/ws.rs

@@ -162,7 +162,7 @@ impl<F> WebSocketUpgrade<F> {
     /// If set to `0` each message will be eagerly written to the underlying stream.
     /// It is often more optimal to allow them to buffer a little, hence the default value.
     ///
-    /// Note: [`flush`](WebSocket::flush) will always fully write the buffer regardless.
+    /// Note: [`flush`](SinkExt::flush) will always fully write the buffer regardless.
     pub fn write_buffer_size(mut self, size: usize) -> Self {
         self.config.write_buffer_size = size;
         self