We should call __vlan_hwaccel_put_tag() only if the packet
comes from vlan, otherwise VLAN_TAG_PRESENT will always be
added.

Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>