fix missing space, add option to exit on error for e.g. console core builds

libretro-buildbot-recipe.sh

@@ -1,3 +1,4 @@
+#!/bin/bash
 # vim: set ts=3 sw=3 noet ft=sh : bash
 # ----- setup -----
 
@@ -273,6 +274,10 @@ buildbot_handle_message() {
 
 	echo buildbot job: $MESSAGE
 	buildbot_log "$MESSAGE"
+
+	if [ "$FAIL_ON_ERROR" = "1" ]; then
+		return 1
+	fi
 }
 
 build_libretro_generic_makefile() {