Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c
index 38748b0..3849478 100644
--- a/tools/lib/bitmap.c
+++ b/tools/lib/bitmap.c
@@ -1,9 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * From lib/bitmap.c
  * Helper functions for bitmap.h.
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
  */
 #include <linux/bitmap.h>