mac80211: ignore AP_VLAN in ieee80211_recalc_chanctx_chantype

When bringing down the AP, a WARN_ON is hit because the bss config chandef
is empty here.
Since AP_VLAN channel settings do not matter for anything chanctx related
(always inherits the settings from the AP interface), let's just ignore
it here.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/chan.c

@@ -541,6 +541,8 @@ static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 			continue;
 		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
 			continue;
+		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+			continue;
 
 		if (!compat)
 			compat = &sdata->vif.bss_conf.chandef;