Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/9p/error.c b/net/9p/error.c
index 126fd0d..231f355 100644
--- a/net/9p/error.c
+++ b/net/9p/error.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/fs/9p/error.c
  *
@@ -9,22 +10,6 @@
  *
  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
- *
- *  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
- *
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt