Remove unused UL_INFO_mutex

The UL_INFO_mutex is used in only one place, and therefore useless.
Also, the scheduler uses a lock internally to prevent concurrent access.
Hence, the UL_INFO_mutex is not needed.

Remove kill_gNB_proc(), as it is now dead code.

nfapi/oai_integration/nfapi_vnf.c

@@ -1244,7 +1244,6 @@ int phy_nr_slot_indication(nfapi_nr_slot_indication_scf_t *ind) {
 
 int phy_nr_srs_indication(nfapi_nr_srs_indication_t *ind) {
   struct PHY_VARS_gNB_s *gNB = RC.gNB[0];
-  pthread_mutex_lock(&gNB->UL_INFO_mutex);
 
   gNB->UL_INFO.srs_ind = *ind;
 
@@ -1260,8 +1259,6 @@ int phy_nr_srs_indication(nfapi_nr_srs_indication_t *ind) {
         );
   }
 
-  pthread_mutex_unlock(&gNB->UL_INFO_mutex);
-
   return 1;
 }
 //end NR phy indication