Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/cmdline.c b/lib/cmdline.c
index 171c19b..fbb9981 100644
--- a/lib/cmdline.c
+++ b/lib/cmdline.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/lib/cmdline.c
  * Helper functions generally used for parsing kernel command line
@@ -5,11 +6,7 @@
  *
  * Code and copyrights come from init/main.c and arch/i386/kernel/setup.c.
  *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
- *
  * GNU Indent formatting options for this file: -kr -i8 -npsl -pcs
- *
  */
 
 #include <linux/export.h>
@@ -135,18 +132,23 @@
 	case 'E':
 	case 'e':
 		ret <<= 10;
+		/* fall through */
 	case 'P':
 	case 'p':
 		ret <<= 10;
+		/* fall through */
 	case 'T':
 	case 't':
 		ret <<= 10;
+		/* fall through */
 	case 'G':
 	case 'g':
 		ret <<= 10;
+		/* fall through */
 	case 'M':
 	case 'm':
 		ret <<= 10;
+		/* fall through */
 	case 'K':
 	case 'k':
 		ret <<= 10;