pxa168_eth: fix a mdiobus leak

mdiobus resources must be released on exit

Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Acked-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/pxa168_eth.c b/drivers/net/pxa168_eth.c
index 410ea0a..85eddda 100644
--- a/drivers/net/pxa168_eth.c
+++ b/drivers/net/pxa168_eth.c
@@ -1606,6 +1606,8 @@
 
 	iounmap(pep->base);
 	pep->base = NULL;
+	mdiobus_unregister(pep->smi_bus);
+	mdiobus_free(pep->smi_bus);
 	unregister_netdev(dev);
 	flush_scheduled_work();
 	free_netdev(dev);