powerpc/vio: Use put_device() on device_register failure

The kernel doc for device_register (and device_initialize) very clearly
state to call put_device not kfree after calling, even on error.

Signed-off-by: Milton Miller <[e-mail]>
Signed-off-by: Nishanth Aravamudan <[e-mail]>
Acked-by: Grant Likely <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/kernel/vio.c

···
 	if (device_register(&viodev->dev)) {
 		printk(KERN_ERR "%s: failed to register device %s\n",
 				__func__, dev_name(&viodev->dev));
-		/* XXX free TCE table */
-		kfree(viodev);
+		put_device(&viodev->dev);
 		return NULL;
 	}