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

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>