Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/testing/vsock/control.c b/tools/testing/vsock/control.c
index 90fd47f..45f328c 100644
--- a/tools/testing/vsock/control.c
+++ b/tools/testing/vsock/control.c
@@ -1,13 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Control socket for client/server test execution
  *
  * Copyright (C) 2017 Red Hat, Inc.
  *
  * Author: Stefan Hajnoczi <stefanha@redhat.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; version 2
- * of the License.
  */
 
 /* The client and server may need to coordinate to avoid race conditions like