mac80211: mark local variable __maybe_unused

The 'local' variable in __ieee80211_vif_copy_chanctx_to_vlans()
is only used/needed when lockdep is compiled in, mark it as such
to avoid compile warnings in the other case.

While at it, fix some indentation where it's used.
Reviewed-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/chan.c

@@ -848,7 +848,7 @@ static void
 __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 				      bool clear)
 {
-	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_local *local __maybe_unused = sdata->local;
 	struct ieee80211_sub_if_data *vlan;
 	struct ieee80211_chanctx_conf *conf;
 
@@ -864,7 +864,7 @@ __ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
 	 * to a channel context that has already been freed.
 	 */
 	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
-				lockdep_is_held(&local->chanctx_mtx));
+					 lockdep_is_held(&local->chanctx_mtx));
 	WARN_ON(!conf);
 
 	if (clear)