net: vlan: fix comment for vlan_ethhdr->h_vlan_proto

After addition of 8021AD h_vlan_proto can be either ETH_P_8021Q or
ETH_P_8021AD.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_vlan.h

@@ -44,7 +44,7 @@ struct vlan_hdr {
  *	struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
  *	@h_dest: destination ethernet address
  *	@h_source: source ethernet address
- *	@h_vlan_proto: ethernet protocol (always 0x8100)
+ *	@h_vlan_proto: ethernet protocol
  *	@h_vlan_TCI: priority and VLAN ID
  *	@h_vlan_encapsulated_proto: packet type ID or len
  */