RDMA/hns: Remove the condition of light load for posting DWQE

RDMA/hns: Remove the condition of light load for posting DWQE

Even in the case of heavy load, direct WQE can still be posted. The
hardware will decide whether to drop the DWQE or not. Thus, the limit
needs to be removed.

Fixes: 934c3c3c127a ("RDMA/hns: Add support of direct wqe")
Link: https://lore.kernel.org/r/1619593950-29414-1-git-send-email-liweihang@huawei.com
Signed-off-by: Yixian Liu <liuyixian@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>