wl1271: Correct TKIP header space handling in TX path

Correct the position to which TKIP header space is appended for TX
packets.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Vidhya Govindan <vidhya.govindan@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index bedd19b..3d629da 100644
--- a/drivers/net/wireless/wl12xx/wl1271_main.c
+++ b/drivers/net/wireless/wl12xx/wl1271_main.c
@@ -1160,12 +1160,9 @@
 
 static int wl1271_init_ieee80211(struct wl1271 *wl)
 {
-	/*
-	 * The tx descriptor buffer and the TKIP space.
-	 *
-	 * FIXME: add correct 1271 descriptor size
-	 */
-	wl->hw->extra_tx_headroom = WL1271_TKIP_IV_SPACE;
+	/* The tx descriptor buffer and the TKIP space. */
+	wl->hw->extra_tx_headroom = WL1271_TKIP_IV_SPACE +
+		sizeof(struct wl1271_tx_hw_descr);
 
 	/* unit us */
 	/* FIXME: find a proper value */