Merge pull request #2198 from ARMmbed/IOTTHD-3691

MAC: changed CCA and TX fail trace level to debug

Author: Jarkko Paso

source/MAC/IEEE802_15_4/mac_mcps_sap.c

@@ -1316,15 +1316,15 @@ static void mac_common_data_confirmation_handle(protocol_interface_rf_mac_setup_
     timer_mac_stop(rf_mac_setup);
     if (m_event == MAC_CCA_FAIL) {
         sw_mac_stats_update(rf_mac_setup, STAT_MAC_TX_CCA_FAIL, 0);
-        tr_error("MAC CCA fail");
+        tr_debug("MAC CCA fail");
         /* CCA fail */
         //rf_mac_setup->cca_failure++;
         buf->status = MLME_BUSY_CHAN;
     } else {
         sw_mac_stats_update(rf_mac_setup, STAT_MAC_TX_COUNT, buf->mac_payload_length);
         if (m_event == MAC_TX_FAIL) {
             sw_mac_stats_update(rf_mac_setup, STAT_MAC_TX_FAIL, 0);
-            tr_error("MAC tx fail");
+            tr_debug("MAC tx fail");
             buf->status = MLME_TX_NO_ACK;
         } else if (m_event == MAC_TX_DONE) {
             if (mac_is_ack_request_set(buf) == false) {