net: usb: cdc_eem: Fix rx skb allocation for 802.1Q VLANs

cdc_eem frames might need to contain 802.1Q VLAN Ethernet frames.
URB/skb sizing from usbnet will default to the hard_mtu,
so account for the VLAN header by expanding that via hard_header_len

Signed-off-by: Ian Coolidge <iancoolidge@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/cdc_eem.c

@@ -31,6 +31,7 @@
 #include <linux/usb/cdc.h>
 #include <linux/usb/usbnet.h>
 #include <linux/gfp.h>
+#include <linux/if_vlan.h>
 
 
 /*
@@ -92,7 +93,7 @@ static int eem_bind(struct usbnet *dev, struct usb_interface *intf)
 
 	/* no jumbogram (16K) support for now */
 
-	dev->net->hard_header_len += EEM_HEAD + ETH_FCS_LEN;
+	dev->net->hard_header_len += EEM_HEAD + ETH_FCS_LEN + VLAN_HLEN;
 	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
 
 	return 0;