mdio: fix non-constant printk warnings

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index bb29ae3..b754020 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -99,7 +99,7 @@
 	bus->dev.parent = bus->parent;
 	bus->dev.class = &mdio_bus_class;
 	bus->dev.groups = NULL;
-	dev_set_name(&bus->dev, bus->id);
+	dev_set_name(&bus->dev, "%s", bus->id);
 
 	err = device_register(&bus->dev);
 	if (err) {