fbdev: imsttfb: Fix error path of imsttfb_probe()

Release ressources when init_imstt() returns failure.
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/imsttfb.c

@@ -1535,7 +1535,9 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto error;
 	info->pseudo_palette = par->palette;
 	ret = init_imstt(info);
-	if (!ret)
+	if (ret)
+		goto error;
+
 	pci_set_drvdata(pdev, info);
 	return ret;