mac80211: let sta_info_get_by_idx get sta by sdata

Instead of filtering by device, directly look up by sdata.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 7f18c8f..7d59181 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -398,13 +398,13 @@
 static int ieee80211_dump_station(struct wiphy *wiphy, struct net_device *dev,
 				 int idx, u8 *mac, struct station_info *sinfo)
 {
-	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct sta_info *sta;
 	int ret = -ENOENT;
 
 	rcu_read_lock();
 
-	sta = sta_info_get_by_idx(local, idx, dev);
+	sta = sta_info_get_by_idx(sdata, idx);
 	if (sta) {
 		ret = 0;
 		memcpy(mac, sta->sta.addr, ETH_ALEN);