mac80211: don't warn when stopping VLAN with stations

Stations assigned to an AP_VLAN type interface are flushed
when the interface is stopped, but then we warn about it.
Suppress the warning since there's nothing else that would
ensure those stations are already removed at this point.

Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/iface.c

@@ -819,13 +819,15 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
 	 * (because if we remove a STA after ops->remove_interface()
 	 * the driver will have removed the vif info already!)
 	 *
-	 * This is relevant only in WDS mode, in all other modes we've
-	 * already removed all stations when disconnecting or similar,
-	 * so warn otherwise.
+	 * In WDS mode a station must exist here and be flushed, for
+	 * AP_VLANs stations may exist since there's nothing else that
+	 * would have removed them, but in other modes there shouldn't
+	 * be any stations.
 	 */
 	flushed = sta_info_flush(sdata);
-	WARN_ON_ONCE((sdata->vif.type != NL80211_IFTYPE_WDS && flushed > 0) ||
-		     (sdata->vif.type == NL80211_IFTYPE_WDS && flushed != 1));
+	WARN_ON_ONCE(sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
+		     ((sdata->vif.type != NL80211_IFTYPE_WDS && flushed > 0) ||
+		      (sdata->vif.type == NL80211_IFTYPE_WDS && flushed != 1)));
 
 	/* don't count this interface for promisc/allmulti while it is down */
 	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)