Fix memory leak and possible crash

nr_dlsim allocates memory on every SNR iteration without freeing it.
This can lead to memory exhaustion. Fix this by allocating only once
and reuse memory. Also, free it before exit.

openair1/SIMULATION/NR_PHY/dlsim.c

@@ -959,6 +959,13 @@ printf("%d\n", slot);
     fprintf(csv_file,"avg_round,eff_rate,eff_throughput,TBS\n");
   }
   //---------------
+
+  Sched_INFO = malloc(sizeof(*Sched_INFO));
+  if (Sched_INFO == NULL) {
+    LOG_E(PHY, "out of memory\n");
+    exit(1);
+  }
+
   for (SNR = snr0; SNR < snr1 && !stop; SNR += .2) {
 
     varArray_t *table_tx=initVarArray(1000,sizeof(double));
@@ -1012,11 +1019,6 @@ printf("%d\n", slot);
       UE_harq_process->DLround = round;
       UE_harq_process->first_rx = 1;
 
-      Sched_INFO = malloc(sizeof(*Sched_INFO));
-      if (Sched_INFO == NULL) {
-        LOG_E(PHY, "out of memory\n");
-        exit(1);
-      }
       memset(Sched_INFO, 0, sizeof(*Sched_INFO));
       Sched_INFO->sched_response_id = -1;
 
@@ -1335,6 +1337,8 @@ printf("%d\n", slot);
     n_errs = n_errors[0];
   } // NSR
 
+  free(Sched_INFO);
+
   free_channel_desc_scm(gNB2UE);
 
   for (i = 0; i < n_tx; i++) {