RDMA/hns: Replace not intuitive function/macro names

Replace "sw2hw" and "hw2sw" which is hard to understand with "create" and
"destroy".

Link: https://lore.kernel.org/r/1572952082-6681-6-git-send-email-liweihang@hisilicon.com


Signed-off-by: Yixing Liu <liuyixing1@huawei.com>
Signed-off-by: Weihang Li <liweihang@hisilicon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>