MAC: Added trace to when CCA fails and packet TX is canceled

Author: Jarkko Paso

source/MAC/IEEE802_15_4/mac_mcps_sap.c

@@ -1316,6 +1316,7 @@ 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");
         /* CCA fail */
         //rf_mac_setup->cca_failure++;
         buf->status = MLME_BUSY_CHAN;