mac80211: use ieee80211_free_txskb in a few more places

Free tx status skbs when draining power save buffers, pending frames, or
when tearing down a vif.
Fixes remaining conditions that can lead to hostapd/wpa_supplicant hangs when
running out of socket write memory.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 22ca350..94e5868 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -406,7 +406,7 @@
 	int queue = info->hw_queue;
 
 	if (WARN_ON(!info->control.vif)) {
-		kfree_skb(skb);
+		ieee80211_free_txskb(&local->hw, skb);
 		return;
 	}
 
@@ -431,7 +431,7 @@
 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 
 		if (WARN_ON(!info->control.vif)) {
-			kfree_skb(skb);
+			ieee80211_free_txskb(&local->hw, skb);
 			continue;
 		}