asix: check packet size against mtu+ETH_HLEN instead of ETH_FRAME_LEN

Driver checks received packet is too large in asix_rx_fixup() and fails if it is. Problem is
that MTU might be set larger than 1500 and asix fails to work correctly with VLAN tagged
packets. The check should be 'dev->net->mtu + ETH_HLEN' instead.

Tested with AX88772.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/asix.c

@@ -344,7 +344,7 @@ static int asix_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 			return 2;
 		}
 
-		if (size > ETH_FRAME_LEN) {
+		if (size > dev->net->mtu + ETH_HLEN) {
 			netdev_err(dev->net, "asix_rx_fixup() Bad RX Length %d\n",
 				   size);
 			return 0;