net: hns3: some modifications to simplify and optimize code

This patch deletes some redundant code and refactors some bloated
functions.

Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Weihang Li <liweihang@hisilicon.com>
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>