mac80211: Cancel the power save timer in ieee80211_stop.

Since the station info is flushed before calling set_disassoc
in ieee80211_stop, the power save timer is never cancelled
when the driver is unloaded. Hence the timer cancellation has
to be done in ieee80211_stop itself.
Signed-off-by: NVivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/iface.c

@@ -383,6 +383,8 @@ static int ieee80211_stop(struct net_device *dev)
 		atomic_dec(&local->iff_promiscs);
 
 	dev_mc_unsync(local->mdev, dev);
+	del_timer_sync(&local->dynamic_ps_timer);
+	cancel_work_sync(&local->dynamic_ps_enable_work);
 
 	/* APs need special treatment */
 	if (sdata->vif.type == NL80211_IFTYPE_AP) {