cfg80211: don't look at wdev->ssid for giwessid

This variable is only used internally, _while_ connected.
If we use it, the sequence

# iwconfig wlan1 essid foo
<connects>
# iwconfig wlan1 essid ""
<disconnects>
# iwconfig

will still display "foo" as the SSID afterwards, which
is obviously quite bogus. Fix this by only displaying
the wext SSID, if present.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/wext-sme.c

@@ -209,11 +209,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
 	data->flags = 0;
 
 	wdev_lock(wdev);
-	if (wdev->ssid_len) {
-		data->flags = 1;
-		data->length = wdev->ssid_len;
-		memcpy(ssid, wdev->ssid, data->length);
-	} else if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) {
+	if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) {
 		data->flags = 1;
 		data->length = wdev->wext.connect.ssid_len;
 		memcpy(ssid, wdev->wext.connect.ssid, data->length);