wifi: ath11k: Remove redundant ath11k_mac_drain_tx

ath11k_mac_drain_tx is already called in ath11k_mac_wait_tx_complete, no need to call it again. So remove it.

This is found in code review.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220919020259.1746-1-quic_bqiang@quicinc.com

drivers/net/wireless/ath/ath11k/wow.c

@@ -703,7 +703,6 @@ int ath11k_wow_op_suspend(struct ieee80211_hw *hw,
 		goto cleanup;
 	}
 
-	ath11k_mac_drain_tx(ar);
 	ret = ath11k_mac_wait_tx_complete(ar);
 	if (ret) {
 		ath11k_warn(ar->ab, "failed to wait tx complete: %d\n", ret);