dmaengine: plx_dma: add a missing put_device() on error path

Add a missing put_device(&pdev->dev) if the call to
dma_async_device_register(dma); fails.

Fixes: 905ca51e

 ("dmaengine: plx-dma: Introduce PLX DMA engine PCI driver skeleton")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/YFnq/0IQzixtAbC1@mwanda


Signed-off-by: Vinod Koul <vkoul@kernel.org>