net: hns3: fix improper error handling for hns3_client_start

If hns3_client_start() failed in the hns3_client_init(),
register_dev() should be undo in its error handling.

Fixes: a6d818e3 ("net: hns3: Add vport alive state checking support")
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>