zd1201: avoid null ptr access of skb->dev

patch 3ba72b25 in mainline.

skb->dev is not set until eth_type_trans is called...
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/wireless/zd1201.c

@@ -327,8 +327,8 @@ static void zd1201_usbrx(struct urb *urb)
 			memcpy(skb_put(skb, 6), &data[datalen-8], 6);
 			memcpy(skb_put(skb, 2), &data[datalen-24], 2);
 			memcpy(skb_put(skb, len), data, len);
-			skb->dev->last_rx = jiffies;
 			skb->protocol = eth_type_trans(skb, zd->dev);
+			skb->dev->last_rx = jiffies;
 			zd->stats.rx_packets++;
 			zd->stats.rx_bytes += skb->len;
 			netif_rx(skb);
@@ -384,8 +384,8 @@ static void zd1201_usbrx(struct urb *urb)
 			memcpy(skb_put(skb, 2), &data[6], 2);
 			memcpy(skb_put(skb, len), data+8, len);
 		}
-		skb->dev->last_rx = jiffies;
 		skb->protocol = eth_type_trans(skb, zd->dev);
+		skb->dev->last_rx = jiffies;
 		zd->stats.rx_packets++;
 		zd->stats.rx_bytes += skb->len;
 		netif_rx(skb);