Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/lru_cache.c b/lib/lru_cache.c
index 2b10a40..c69ee53 100644
--- a/lib/lru_cache.c
+++ b/lib/lru_cache.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
    lru_cache.c
 
@@ -7,19 +8,6 @@
    Copyright (C) 2003-2008, Philipp Reisner <philipp.reisner@linbit.com>.
    Copyright (C) 2003-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
 
-   drbd is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
-
-   drbd 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 drbd; see the file COPYING.  If not, write to
-   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 
  */