Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/ceph/cache.c b/fs/ceph/cache.c
index 1bf3502..b2ec29e 100644
--- a/fs/ceph/cache.c
+++ b/fs/ceph/cache.c
@@ -1,26 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Ceph cache definitions.
  *
  *  Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved.
  *  Written by Milosz Tanski (milosz@adfin.com)
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2
- *  as published by the Free Software Foundation.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to:
- *  Free Software Foundation
- *  51 Franklin Street, Fifth Floor
- *  Boston, MA  02111-1301  USA
- *
  */
 
+#include <linux/ceph/ceph_debug.h>
+
 #include "super.h"
 #include "cache.h"