scsi: a4000 - Correct driver unregistration in case of failure

commit 7a192ec3 ("platform driver: fix
incorrect use of 'platform_bus_type' with 'struct device_driver') turned a
driver_UNregister into platform_driver_REGISTER. Correct this to
platform_driver_UNregister.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>

drivers/scsi/a4000t.c

@@ -129,7 +129,7 @@ static int __init a4000t_scsi_init(void)
 	a4000t_scsi_device = platform_device_register_simple("a4000t-scsi",
 			-1, NULL, 0);
 	if (IS_ERR(a4000t_scsi_device)) {
-		platform_driver_register(&a4000t_scsi_driver);
+		platform_driver_unregister(&a4000t_scsi_driver);
 		return PTR_ERR(a4000t_scsi_device);
 	}