BugLink: http://bugs.launchpad.net/bugs/1664312

Fix to return a negative error code from the invalid dma width
error handling case instead of 0.
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 6e22066f)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>