Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/raid6/test/Makefile b/lib/raid6/test/Makefile
index 7977764..3ab8720 100644
--- a/lib/raid6/test/Makefile
+++ b/lib/raid6/test/Makefile
@@ -34,6 +34,9 @@
 
 ifeq ($(IS_X86),yes)
         OBJS   += mmx.o sse1.o sse2.o avx2.o recov_ssse3.o recov_avx2.o avx512.o recov_avx512.o
+        CFLAGS += $(shell echo "pshufb %xmm0, %xmm0" |		\
+                    gcc -c -x assembler - >&/dev/null &&	\
+                    rm ./-.o && echo -DCONFIG_AS_SSSE3=1)
         CFLAGS += $(shell echo "vpbroadcastb %xmm0, %ymm1" |	\
                     gcc -c -x assembler - >&/dev/null &&	\
                     rm ./-.o && echo -DCONFIG_AS_AVX2=1)
diff --git a/lib/raid6/test/test.c b/lib/raid6/test/test.c
index b07f4d8..a3cf071 100644
--- a/lib/raid6/test/test.c
+++ b/lib/raid6/test/test.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* -*- linux-c -*- ------------------------------------------------------- *
  *
  *   Copyright 2002-2007 H. Peter Anvin - All Rights Reserved
  *
- *   This file is part of the Linux kernel, and is made available under
- *   the terms of the GNU General Public License version 2 or (at your
- *   option) any later version; incorporated herein by reference.
- *
  * ----------------------------------------------------------------------- */
 
 /*