Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile
index 0b76d88..f3d494a 100644
--- a/arch/um/kernel/skas/Makefile
+++ b/arch/um/kernel/skas/Makefile
@@ -1,6 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
-# Licensed under the GPL
 #
 
 obj-y := clone.o mmu.o process.o syscall.o uaccess.o
@@ -12,4 +12,6 @@
 CFLAGS_clone.o := $(CFLAGS_NO_HARDENING)
 UNPROFILE_OBJS := clone.o
 
+KCOV_INSTRUMENT := n
+
 include arch/um/scripts/Makefile.rules