scripts/setlocalversion: simplify the short version part

Reduce the indentation.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>

scripts/setlocalversion

@@ -131,15 +131,13 @@ res="${res}${CONFIG_LOCALVERSION}${LOCALVERSION}"
 if test "$CONFIG_LOCALVERSION_AUTO" = "y"; then
 	# full scm version string
 	res="$res$(scm_version)"
-else
+elif [ -z "${LOCALVERSION}" ]; then
 	# append a plus sign if the repository is not in a clean
 	# annotated or signed tagged state (as git describe only
 	# looks at signed or annotated tags - git tag -a/-s) and
 	# LOCALVERSION= is not specified
-	if test "${LOCALVERSION+set}" != "set"; then
-		scm=$(scm_version --short)
-		res="$res${scm:++}"
-	fi
+	scm=$(scm_version --short)
+	res="$res${scm:++}"
 fi
 
 echo "$res"