FlexRAN: Simplify stats request handling

* only set up timer for sending requests
* simplify interface for timer setup
* on timer expiry, do not pass through stats request function but
  directly send the reply
* Remove whatever report structure and use stats request directly for
  inferring the data to send

openair2/ENB_APP/flexran_agent.c

@@ -202,8 +202,6 @@ int flexran_agent_start(mid_t mod_id)
    *flexran_agent_register_channel(mod_id, channel, FLEXRAN_AGENT_MAC);
    */
 
-  /*Initialize the continuous stats update mechanism*/
-  flexran_agent_init_cont_stats_update(mod_id);
   pthread_t t; 
   threadCreate(&t, receive_thread, flexran, "flexran", -1, OAI_PRIORITY_RT);