qcacld-3.0: Remove offchannel_tx_event member in hdd_adapter

The offchannel_tx_event member in the hdd_adapter structure has
no references in the driver so remove this obsolete variable.
The code that previously used this variable was removed by Change-Id:
Idaaacac4fdaf1b964432c33c10b1c86f8a591c2d

Change-Id: Icf51105e0c3e04ec2e1b26aa6c7a36a017b4c573
CRs-Fixed: 3213567

core/hdd/inc/wlan_hdd_main.h

@@ -1378,8 +1378,6 @@ struct hdd_adapter {
 	/* completion variable for Linkup Event */
 	struct completion linkup_event_var;
 
-	/* completion variable for off channel  remain on channel Event */
-	struct completion offchannel_tx_event;
 	/* Completion variable for action frame */
 	struct completion tx_action_cnf_event;
 

core/hdd/src/wlan_hdd_main.c

@@ -7591,7 +7591,6 @@ static void hdd_init_completion(struct hdd_adapter *adapter)
 	init_completion(&adapter->disconnect_comp_var);
 	init_completion(&adapter->linkup_event_var);
 	init_completion(&adapter->sta_authorized_event);
-	init_completion(&adapter->offchannel_tx_event);
 	init_completion(&adapter->tx_action_cnf_event);
 	init_completion(&adapter->lfr_fw_status.disable_lfr_event);
 }