rndis_wlan: do not set default_key if not WEP key

rndis_set_default_key did call add_wep_key to set default key on device, even
if key is WPA. This caused rndis_wlan not work with wpa_supplicant in nl80211
mode (causing disconnect from AP).

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c
index de4c050..9e6105c 100644
--- a/drivers/net/wireless/rndis_wlan.c
+++ b/drivers/net/wireless/rndis_wlan.c
@@ -2435,6 +2435,9 @@
 
 	priv->encr_tx_key_index = key_index;
 
+	if (is_wpa_key(priv, key_index))
+		return 0;
+
 	key = priv->encr_keys[key_index];
 
 	return add_wep_key(usbdev, key.material, key.len, key_index);