RDMA/hns: Optimize hns_roce_config_link_table()

Remove the unnecessary memset operation and adjust style of some lines in
hns_roce_config_link_table().

Link: https://lore.kernel.org/r/1586938475-37049-2-git-send-email-liweihang@huawei.com


Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>