mac80211: sta_info: Add lockdep condition for RCU list usage

The function sta_info_get_by_idx() uses RCU list primitive.
It is called with  local->sta_mtx held from mac80211/cfg.c.
Add lockdep expression to avoid any false positive RCU list warnings.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Link: https://lore.kernel.org/r/20200409082906.27427-1-madhuparnabhowmik10@gmail.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/sta_info.c

@@ -231,7 +231,8 @@ struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
 	struct sta_info *sta;
 	int i = 0;
 
-	list_for_each_entry_rcu(sta, &local->sta_list, list) {
+	list_for_each_entry_rcu(sta, &local->sta_list, list,
+				lockdep_is_held(&local->sta_mtx)) {
 		if (sdata != sta->sdata)
 			continue;
 		if (i < idx) {