wireless: Remove unnecessary casts of usb_get_intfdata

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/carl9170/usb.c b/drivers/net/wireless/ath/carl9170/usb.c
index a268053..2d947a3 100644
--- a/drivers/net/wireless/ath/carl9170/usb.c
+++ b/drivers/net/wireless/ath/carl9170/usb.c
@@ -160,8 +160,7 @@
 
 static void carl9170_usb_tx_data_complete(struct urb *urb)
 {
-	struct ar9170 *ar = (struct ar9170 *)
-	      usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
+	struct ar9170 *ar = usb_get_intfdata(usb_ifnum_to_if(urb->dev, 0));
 
 	if (WARN_ON_ONCE(!ar)) {
 		dev_kfree_skb_irq(urb->context);