cfg80211/mac80211: correct qos-map locking

Since the RTNL can't always be held, use wdev/sdata locking for
the qos-map dereference in mac80211. This requires cfg80211 to
consistently lock it, which it was missing in one place.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 5618888..329b0ef 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -879,7 +879,9 @@
 
 		dev->ieee80211_ptr->use_4addr = false;
 		dev->ieee80211_ptr->mesh_id_up_len = 0;
+		wdev_lock(dev->ieee80211_ptr);
 		rdev_set_qos_map(rdev, dev, NULL);
+		wdev_unlock(dev->ieee80211_ptr);
 
 		switch (otype) {
 		case NL80211_IFTYPE_AP: