RDMA/hns: Simplify attribute judgment code

Combine attribute flags before masking them.

Link: https://lore.kernel.org/r/1584674622-52773-4-git-send-email-liweihang@huawei.com


Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>