Change variable types in statistics to accommodate more bytes and to avoid negative values

When running gNB for a long time and transferring high amount of data, statistics become negative (and later in an arithmetic overflow) because they are too short for such amount of bytes. Example: UE 0: ulsch_total_bytes_scheduled -1804219593, ulsch_total_bytes_received -1804223769

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_uci.c

@@ -582,7 +582,7 @@ static void handle_dl_harq(module_id_t mod_id,
     harq->ndi ^= 1;
     NR_mac_stats_t *stats = &UE_info->mac_stats[UE_id];
     stats->dlsch_errors++;
-    LOG_D(NR_MAC, "retransmission error for UE %d (total %d)\n", UE_id, stats->dlsch_errors);
+    LOG_D(NR_MAC, "retransmission error for UE %d (total %"PRIu64")\n", UE_id, stats->dlsch_errors);
   } else {
     add_tail_nr_list(&UE_info->UE_sched_ctrl[UE_id].retrans_dl_harq, harq_pid);
     harq->round++;