net: hns3: Resume promisc mode and vlan filter status after loopback test

This patch resumes promisc mode and vlan filter status after
loopback test.

Fixes: 3b75c3df

 ("net: hns3: net: hns3: Add support for IFF_ALLMULTI flag")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>