net: fix docs for recv_buffer_size method (#7336)

Author: jscptman

tokio/src/net/tcp/socket.rs

@@ -368,7 +368,7 @@ impl TcpSocket {
     ///
     /// Note that if [`set_recv_buffer_size`] has been called on this socket
     /// previously, the value returned by this function may not be the same as
-    /// the argument provided to `set_send_buffer_size`. This is for the
+    /// the argument provided to `set_recv_buffer_size`. This is for the
     /// following reasons:
     ///
     /// * Most operating systems have minimum and maximum allowed sizes for the