Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/debug_locks.c b/lib/debug_locks.c
index 124fdf2..a75ee30 100644
--- a/lib/debug_locks.c
+++ b/lib/debug_locks.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * lib/debug_locks.c
  *
@@ -21,7 +22,7 @@
  * that would just muddy the log. So we report the first one and
  * shut up after that.
  */
-int debug_locks = 1;
+int debug_locks __read_mostly = 1;
 EXPORT_SYMBOL_GPL(debug_locks);
 
 /*
@@ -29,7 +30,7 @@
  * 'silent failure': nothing is printed to the console when
  * a locking bug is detected.
  */
-int debug_locks_silent;
+int debug_locks_silent __read_mostly;
 EXPORT_SYMBOL_GPL(debug_locks_silent);
 
 /*