Bug 612408: return NS_ERROR_FAILURE instead of NULL in failure case within mozJSComponentLoader::ImportInto. r=gal

js/src/xpconnect/loader/mozJSComponentLoader.cpp

@@ -1497,7 +1497,7 @@ mozJSComponentLoader::ImportInto(const nsACString & aLocation,
 
         JSAutoEnterCompartment ac;
         if (!ac.enter(mContext, mod->global))
-            return NULL;
+            return NS_ERROR_FAILURE;
 
         if (!JS_GetProperty(mContext, mod->global,
                             "EXPORTED_SYMBOLS", &symbols)) {