Do not reset metrics in the hub

lib/include/srslte/common/metrics_hub.h

@@ -64,7 +64,6 @@ private:
     uint32_t period = sleep_period_start[0].tv_sec*1e6 + sleep_period_start[0].tv_usec;
     if (m) {
       metrics_t metric;
-      bzero(&metric, sizeof(metrics_t));
       m->get_metrics(metric);
       for (uint32_t i=0;i<listeners.size();i++) {
         listeners[i]->set_metrics(metric, period);