merge_config.sh: Check error codes from make

When we execute make after merging the configurations we ignore any
errors it produces causing whatever is running merge_config.sh to be
unaware of any failures.  This issue was noticed by Guillaume Tucker
while looking at problems with testing of clang only builds in KernelCI
which caused Kbuild to be unable to find a working host compiler.

This implementation was suggested by Yamada-san.
Suggested-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reported-by: NGuillaume Tucker <guillaume.tucker@collabora.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

scripts/kconfig/merge_config.sh

@@ -13,12 +13,12 @@
 #  Copyright (c) 2009-2010 Wind River Systems, Inc.
 #  Copyright 2011 Linaro
 
+set -e
+
 clean_up() {
 	rm -f $TMP_FILE
 	rm -f $MERGE_FILE
-	exit
 }
-trap clean_up HUP INT TERM
 
 usage() {
 	echo "Usage: $0 [OPTIONS] [CONFIG [...]]"
@@ -110,6 +110,9 @@ TMP_FILE=$(mktemp ./.tmp.config.XXXXXXXXXX)
 MERGE_FILE=$(mktemp ./.merge_tmp.config.XXXXXXXXXX)
 
 echo "Using $INITFILE as base"
+
+trap clean_up EXIT
+
 cat $INITFILE > $TMP_FILE
 
 # Merge files, printing warnings on overridden values
@@ -155,7 +158,6 @@ if [ "$RUNMAKE" = "false" ]; then
 	echo "#"
 	echo "# merged configuration written to $KCONFIG_CONFIG (needs make)"
 	echo "#"
-	clean_up
 	exit
 fi
 
@@ -185,5 +187,3 @@ for CFG in $(sed -n -e "$SED_CONFIG_EXP1" -e "$SED_CONFIG_EXP2" $TMP_FILE); do
 		echo ""
 	fi
 done
-
-clean_up