We accidentally return success if dmaengine_submit() fails.  The fix is
to preserve the error code from dma_submit_error().
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NSerge Semin <fancer.lancer@gmail.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>