setlocalversion: absorb $(KERNELVERSION)

Print $(KERNELVERSION) in setlocalversion so that the callers get
simpler.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/setlocalversion

@@ -102,6 +102,11 @@ if ! test -e include/config/auto.conf; then
 	exit 1
 fi
 
+if [ -z "${KERNELVERSION}" ]; then
+	echo "KERNELVERSION is not set" >&2
+	exit 1
+fi
+
 # localversion* files in the build and source directory
 res="$(collect_files localversion*)"
 if test ! "$srctree" -ef .; then
@@ -127,4 +132,4 @@ elif [ "${LOCALVERSION+set}" != "set" ]; then
 	res="$res$(scm_version --short)"
 fi
 
-echo "$res"
+echo "${KERNELVERSION}${res}"