IB/qib: Fix an error code in qib_sdma_verbs_send()

mainline inclusion
from mainline-5.0-rc1
commit 5050ae5f
category: bugfix
bugzilla: 6535
CVE: NA

----------------------

We accidentally return success on this error path.

Fixes: f931551b ("IB/qib: Add new qib driver for QLogic PCIe InfiniBand adapters")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jing xiangfeng <jingxiangfeng@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>