mac80211: purge remain-on-channel items when suspending

They can't really be executed while suspended and could
trigger work warnings, so abort all ROC items. When the
system resumes the notifications about this will be
delivered to userspace which can then act accordingly
(though it will assume they were canceled/finished.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index b01eb73..e19d6cf 100644
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -436,15 +436,15 @@
 	INIT_LIST_HEAD(&local->roc_list);
 }
 
-void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
+void ieee80211_roc_purge(struct ieee80211_local *local,
+			 struct ieee80211_sub_if_data *sdata)
 {
-	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_roc_work *roc, *tmp;
 	LIST_HEAD(tmp_list);
 
 	mutex_lock(&local->mtx);
 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
-		if (roc->sdata != sdata)
+		if (sdata && roc->sdata != sdata)
 			continue;
 
 		if (roc->started && local->ops->remain_on_channel) {