check returned value from system()

git-svn-id: http://svn.eurecom.fr/openair4G/trunk@6231 818b1a75-f10b-46b9-bf7c-635c3b92a50f

openair-cn/SGW-LITE/spgw_config.c

@@ -136,7 +136,7 @@ int spgw_system(char *command_pP, int abort_on_errorP) {
   if (command_pP) {
       SPGW_APP_INFO("system command: %s\n",command_pP);
       ret = system(command_pP);
-      if (ret < 0) {
+      if (ret != 0) {
           SPGW_APP_ERROR("ERROR in system command %s: %d\n",
                      command_pP,ret);
           if (abort_on_errorP) {