avoid hanging when multiple threads are waiting on mreg changes

transport/rdma.c

@@ -375,13 +375,11 @@ mstro_transport_rdma_src_execute_bh(Mstro__Pool__TransferCompleted *tc)
 
   HASH_DEL(g_mstro_transport_mreg_table, regentry);
   free(regentry);
-  if (HASH_COUNT(g_mstro_transport_mreg_table) == 0) {
   err = pthread_cond_signal(&g_mstro_transport_mreg_table_cond);
   if (err) {
-      ERR("Couldn't signal mreg table is empty\n");
+      ERR("Couldn't signal mreg entry change\n");
       status = MSTRO_FAIL;
   }
-  }
 
 BAILOUT_UNLOCK:
   err = pthread_mutex_unlock(&g_mstro_transport_mreg_table_lock);