asix: allow full size 8021Q frames to be received

asix driver drops 8021Q full size frames because it doesn't take into
account VLAN header size.

Tested on AX88772 adapter.

Signed-off-by: Eric Dumazet <edumazet@google.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Allan Chou <allan@asix.com.tw>
CC: Trond Wuellner <trond@chromium.org>
CC: Grant Grundler <grundler@chromium.org>
CC: Paul Stewart <pstew@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/asix.c b/drivers/net/usb/asix.c
index 71e2b05..3ae80ec 100644
--- a/drivers/net/usb/asix.c
+++ b/drivers/net/usb/asix.c
@@ -35,6 +35,7 @@
 #include <linux/crc32.h>
 #include <linux/usb/usbnet.h>
 #include <linux/slab.h>
+#include <linux/if_vlan.h>
 
 #define DRIVER_VERSION "22-Dec-2011"
 #define DRIVER_NAME "asix"
@@ -321,7 +322,7 @@
 			return 0;
 		}
 
-		if ((size > dev->net->mtu + ETH_HLEN) ||
+		if ((size > dev->net->mtu + ETH_HLEN + VLAN_HLEN) ||
 		    (size + offset > skb->len)) {
 			netdev_err(dev->net, "asix_rx_fixup() Bad RX Length %d\n",
 				   size);