Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/perf/util/genelf_debug.c b/tools/perf/util/genelf_debug.c
index 40789d8..30e9f61 100644
--- a/tools/perf/util/genelf_debug.c
+++ b/tools/perf/util/genelf_debug.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * genelf_debug.c
  * Copyright (C) 2015, Google, Inc
@@ -5,8 +6,6 @@
  * Contributed by:
  * 	Stephane Eranian <eranian@google.com>
  *
- * Released under the GPL v2.
- *
  * based on GPLv2 source code from Oprofile
  * @remark Copyright 2007 OProfile authors
  * @author Philippe Elie
@@ -25,7 +24,6 @@
 #include <err.h>
 #include <dwarf.h>
 
-#include "perf.h"
 #include "genelf.h"
 #include "../util/jitdump.h"