net: hns: fixes the issue by using ethtool -s

  before this patch, hns driver only permits user to set the net device
by using ethtool -s when the device is link up. it is obviously not so
good. it needs to be set no matter it is link up or down. so this patch
fixes this issue.

Signed-off-by: yankejian <yankejian@huawei.com>
Signed-off-by: Yisen Zhuang <yisen.zhuang@huawei.com>
Signed-off-by: lisheng <lisheng011@huawei.com>
Signed-off-by: lipeng <lipeng321@huawei.com>
Signed-off-by: Chenny Xu <chenny.xu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>