correctly check for MAC presence in FlexRAN RAN API

openair2/ENB_APP/flexran_agent_ran_api.c

@@ -131,7 +131,7 @@ int8_t flexran_get_ue_phr(mid_t mod_id, mid_t ue_id)
 
 uint8_t flexran_get_ue_wcqi(mid_t mod_id, mid_t ue_id)
 {
-  if (!phy_is_present(mod_id, 0)) return 0;
+  if (!mac_is_present(mod_id)) return 0;
   return RC.mac[mod_id]->UE_list.UE_sched_ctrl[ue_id].dl_cqi[0];
 }