ath11k: avoid unnecessary BH disable lock in STA kickout event

In STA kickout event processing, the peer object is protected
under spin lock BH. Release this lock after picking up the vdev_id
from the peer object instead after ieee80211_report_low_ack().
This will minimize the lock hold period which will improve
performance since base_lock is used across the data path.
This was found in code review.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.5.0.1-00729-QCAHKSWPL_SILICONZ-3 v2
Signed-off-by: Karthikeyan Periyasamy <quic_periyasa@quicinc.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1636560388-24955-1-git-send-email-quic_periyasa@quicinc.com

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

@@ -6399,6 +6399,7 @@ static void ath11k_peer_sta_kickout_event(struct ath11k_base *ab, struct sk_buff
 	struct ieee80211_sta *sta;
 	struct ath11k_peer *peer;
 	struct ath11k *ar;
+	u32 vdev_id;
 
 	if (ath11k_pull_peer_sta_kickout_ev(ab, skb, &arg) != 0) {
 		ath11k_warn(ab, "failed to extract peer sta kickout event");
@@ -6414,10 +6415,15 @@ static void ath11k_peer_sta_kickout_event(struct ath11k_base *ab, struct sk_buff
 	if (!peer) {
 		ath11k_warn(ab, "peer not found %pM\n",
 			    arg.mac_addr);
+		spin_unlock_bh(&ab->base_lock);
 		goto exit;
 	}
 
-	ar = ath11k_mac_get_ar_by_vdev_id(ab, peer->vdev_id);
+	vdev_id = peer->vdev_id;
+
+	spin_unlock_bh(&ab->base_lock);
+
+	ar = ath11k_mac_get_ar_by_vdev_id(ab, vdev_id);
 	if (!ar) {
 		ath11k_warn(ab, "invalid vdev id in peer sta kickout ev %d",
 			    peer->vdev_id);
@@ -6438,7 +6444,6 @@ static void ath11k_peer_sta_kickout_event(struct ath11k_base *ab, struct sk_buff
 	ieee80211_report_low_ack(sta, 10);
 
 exit:
-	spin_unlock_bh(&ab->base_lock);
 	rcu_read_unlock();
 }