ath10k: ensure txrx-compl-task is stopped when cleaning htt-tx

Otherwise, the txrx-compl-task may access some bad memory?
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/htt_tx.c

@@ -390,6 +390,8 @@ void ath10k_htt_tx_free(struct ath10k_htt *htt)
 {
 	int size;
 
+	tasklet_kill(&htt->txrx_compl_task);
+
 	idr_for_each(&htt->pending_tx, ath10k_htt_tx_clean_up_pending, htt->ar);
 	idr_destroy(&htt->pending_tx);