net: hns3: fix for loopback failure when vlan filter is enable

mainline inclusion
from mainline-v4.17-rc1
commit f96818a7
category: bugfix
bugzilla: NA
CVE: NA

----------------------------

When vlan ctag filter is enabled, the loopback selftest fails because
loopback selftest does not support vlan.

This patch fixes it by disabling the vlan ctag filter when runnig
loopback selftest.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Reviewed-by: Yongxin Li <liyongxin1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>