mac80211: Clear wowlan flag when drv_suspend returns failure

drv_resume can get called without a prior call to drv_suspend.
Consider the following steps:

1. Suspend is started but driver's drv_suspend returns error.
2. Suspend is aborted. local->wowlan flag is left set.
3. Interface is removed.
4. Suspend again. This time open_count is 0 so drv_suspend is
   not called and local->wowlan not cleared.
5. On resume ieee80211_reconfig will call drv_resume since
   local->wowlan is set.
Signed-off-by: Pontus Fuchs <pontus.fuchs@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/pm.c

@@ -77,6 +77,7 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 		int err = drv_suspend(local, wowlan);
 		if (err < 0) {
 			local->quiescing = false;
+			local->wowlan = false;
 			return err;
 		} else if (err > 0) {
 			WARN_ON(err != 1);