staging: xillybus: fix error return code in xilly_probe()

Fix to return negative error code -EIO from the error handling
case instead of 0.

Signed-off-by: Wei Yongjun <[e-mail]>
Reviewed-by: Jingoo Han <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/xillybus/xillybus_pcie.c

···
 	}
 
 	endpoint->registers = pci_iomap(pdev, 0, 128);
-
 	if (!endpoint->registers) {
 		dev_err(endpoint->dev, "Failed to map BAR 0. Aborting.\n");
+		rc = -EIO;
 		goto failed_iomap0;
 	}