fpga: dfl: afu: Pass the correct device to dma_mapping_error()

dma_mapping_error() was being called on a different device struct than
what was passed to map/unmap.  Besides rendering the error checking
ineffective, it caused a debug splat with CONFIG_DMA_API_DEBUG.
Signed-off-by: Scott Wood <swood@redhat.com>
Acked-by: Wu Hao <hao.wu@intel.com>
Acked-by: Moritz Fischer <mdf@kernel.org>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/fpga/dfl-afu-dma-region.c

@@ -399,7 +399,7 @@ int afu_dma_map_region(struct dfl_feature_platform_data *pdata,
 				    region->pages[0], 0,
 				    region->length,
 				    DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(&pdata->dev->dev, region->iova)) {
+	if (dma_mapping_error(dfl_fpga_pdata_to_parent(pdata), region->iova)) {
 		dev_err(&pdata->dev->dev, "failed to map for dma\n");
 		ret = -EFAULT;
 		goto unpin_pages;