net: hns3: fix always enable rx vlan filter problem after selftest

Currently, the rx vlan filter will always be disabled before selftest and
be enabled after selftest as the rx vlan filter feature is fixed on in
old device earlier than V3.

However, this feature is not fixed in some new devices and it can be
disabled by user. In this case, it is wrong if rx vlan filter is enabled
after selftest. So fix it.

Fixes: bcc26e8d ("net: hns3: remove unused code in hns3_self_test()")
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>