misc: cardreader: Return -EBUSY if regions are busy

cardreader returns -ENOMEM if a PCI region is currently in use
("requested") by another driver. The proper return code for this is
-EBUSY.

Replace -ENOMEM with -EBUSY.

Signed-off-by: Philipp Stanner <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/cardreader/alcor_pci.c

···
 	ret = pcim_request_all_regions(pdev, DRV_NAME_ALCOR_PCI);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot request region\n");
-		ret = -ENOMEM;
+		ret = -EBUSY;
 		goto error_free_ida;
 	}