Revert "RDMA/hns: Reserve one sge in order to avoid local length error"

This patch caused some issues on SEND operation, and it should be reverted
to make the drivers work correctly. There will be a better solution that
has been tested carefully to solve the original problem.

This reverts commit 711195e5.

Fixes: 711195e5 ("RDMA/hns: Reserve one sge in order to avoid local length error")
Link: https://lore.kernel.org/r/1597829984-20223-1-git-send-email-liweihang@huawei.com


Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>