mac80211: do not pass AP VLAN vif pointers to drivers

This fixes frequent WARN_ONs when using AP VLAN + aggregation, as these vifs
are virtual and not registered with drivers.
Use sta_info_get_bss instead of sta_info_get in aggregation callbacks, so
that these callbacks can find the station entry when called with the AP vif.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index a2d9654..266cc87 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -555,7 +555,7 @@
 	}
 
 	mutex_lock(&local->sta_mtx);
-	sta = sta_info_get(sdata, ra);
+	sta = sta_info_get_bss(sdata, ra);
 	if (!sta) {
 		mutex_unlock(&local->sta_mtx);
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -684,7 +684,7 @@
 
 	mutex_lock(&local->sta_mtx);
 
-	sta = sta_info_get(sdata, ra);
+	sta = sta_info_get_bss(sdata, ra);
 	if (!sta) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "Could not find station: %pM\n", ra);