2.6.x kernels require a similar logic change as commit e1653c3e
[gianfar: do vlan cleanup] and commit 51b8cbfc
[gianfar: fix bug caused by e1653c3e] introduces for newer kernels.

Since there is something wrong with tx vlan of gianfar nic driver,
in kernel(3.1+), tx vlan is disabled. But in kernel 2.6.x, tx vlan
is still enabled. Thus,gianfar nic driver can not support vlan
packets and non-vlan packets at the same time.
Signed-off-by: Zhu Yanjun <Yanjun.Zhu@windriver.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>