mac80211: complete scan work immediately if quiesced or suspended

It is possible that a deferred scan is queued after the queues are
flushed in __ieee80211_suspend().  The deferred scan work may be
scheduled by ROC or ieee80211_stop_poll().

To make sure don't start a new scan while suspending, check whether
we're quiescing or suspended and complete the scan immediately if
that's the case.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/scan.c

@@ -828,6 +828,11 @@ void ieee80211_scan_work(struct work_struct *work)
 
 	mutex_lock(&local->mtx);
 
+	if (!ieee80211_can_run_worker(local)) {
+		aborted = true;
+		goto out_complete;
+	}
+
 	sdata = rcu_dereference_protected(local->scan_sdata,
 					  lockdep_is_held(&local->mtx));
 	scan_req = rcu_dereference_protected(local->scan_req,