Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 39a6f4bc ("b44: replace the ssb_dma API with the generic DMA API")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/1605582131-36735-1-git-send-email-zhangchangzhong@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>