net: vlan: add protocol argument to packet tagging functions

Add a protocol argument to the VLAN packet tagging functions. In case of HW
tagging, we need that protocol available in the ndo_start_xmit functions,
so it is stored in a new field in the skb. The new field fits into a hole
(on 64 bit) and doesn't increase the sks's size.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index b7e9cd7..cc6dfe4 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -221,7 +221,7 @@
 
 	/* map MBIM session to VLAN */
 	if (tci)
-		vlan_put_tag(skb, tci);
+		vlan_put_tag(skb, htons(ETH_P_8021Q), tci);
 err:
 	return skb;
 }