RDMA/hns: Fixes missing error code of CMDQ

When posting a multi-descriptors command, the error code of previous
failed descriptors may be rewrote to 0 by a later successful descriptor.

Fixes: a04ff739 ("RDMA/hns: Add command queue support for hip08 RoCE driver")
Link: https://lore.kernel.org/r/1612688143-28226-3-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@nvidia.com>