[SCSI] scsi_dh_rdac: Fix error path

If create_singlethread_workqueue() failes, rdac_init should fail too.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: "Moger, Babu" <Babu.Moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/device_handler/scsi_dh_rdac.c

@@ -953,6 +953,8 @@ static int __init rdac_init(void)
 	if (!kmpath_rdacd) {
 		scsi_unregister_device_handler(&rdac_dh);
 		printk(KERN_ERR "kmpath_rdacd creation failed.\n");
+
+		r = -EINVAL;
 	}
 done:
 	return r;