mac80211: fix connection polling

Commit 392b9ffb ("mac80211: change beacon/connection polling")
removed the IEEE80211_STA_BEACON_POLL flag.

However, it accidentally removed the setting of
IEEE80211_STA_CONNECTION_POLL, making the connection polling
completely useless (the flag is always clear, so the result
is never being checked). Fix it.
Signed-off-by: Eliad Peller <eliad@wizery.com>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -1910,6 +1910,8 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
 	if (ifmgd->flags & IEEE80211_STA_CONNECTION_POLL)
 		already = true;
 
+	ifmgd->flags |= IEEE80211_STA_CONNECTION_POLL;
+
 	mutex_unlock(&sdata->local->mtx);
 
 	if (already)