wl1271: Fix WEP key handling

WEP key index handling was broken: the default key when using key 0 was never
specified to the FW, and if using other default than 0, it would be set on the
TX path for every single TX'd frame.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/wl12xx/wl1271_tx.c

@@ -203,6 +203,7 @@ static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
 			ret = wl1271_cmd_set_default_wep_key(wl, idx);
 			if (ret < 0)
 				return ret;
+			wl->default_key = idx;
 		}
 	}