Properly cast dist_to_interval to avoid overflow

packet-exchange/src/server.c

@@ -146,10 +146,10 @@ static void *packet_receiving_thread(void *p) {
         stats->max_interval = diff > stats->max_interval ? diff : stats->max_interval;
 
         if(enable_histograms) {
-          dist_to_interval = (diff - param->interval) / 1000;
+          dist_to_interval = (((int64_t)diff) - param->interval) / 1000;
           dist_to_interval += MAX_HIST_VAL / 2;
           if( dist_to_interval > ((int)MAX_HIST_VAL) || dist_to_interval < 0 ) {
-            fprintf(stderr, "jitter higher than MAX_HIST_VAL\n");
+            fprintf(stderr, "jitter higher than MAX_HIST_VAL: %" PRIi64 "\n", dist_to_interval);
             exit(EXIT_FAILURE);
           }
           else {