RDMA/hns: Rename wqe buffer related functions

RDMA/hns: Rename wqe buffer related functions

There are serval global functions related to wqe buffer in the hns driver
and are called in different files. These symbols cannot directly represent
the namespace they belong to. So add prefix 'hns_roce_' to 3 wqe buffer
related global functions: get_recv_wqe(), get_send_wqe(), and
get_send_extend_sge().

Link: https://lore.kernel.org/r/1583839084-31579-2-git-send-email-liweihang@huawei.com
Signed-off-by: Xi Wang <wangxi11@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>