gianfar: Fixup use of BUS_ID_SIZE

Commit b31a1d8b41513b96e9c7ec2f68c5734cef0b26a4 ("gianfar: Convert
gianfar to an of_platform_driver") went back to using BUS_ID_SIZE
instead of sizeof() as per the larger patch series that will remove
"char bus_id[20]" from struct device.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/gianfar.c

@@ -238,8 +238,8 @@ static int gfar_of_init(struct net_device *dev)
 			goto err_out;
 		}
 
-		snprintf(priv->phy_bus_id, BUS_ID_SIZE, PHY_ID_FMT, "0",
-				fixed_link[0]);
+		snprintf(priv->phy_bus_id, sizeof(priv->phy_bus_id),
+				PHY_ID_FMT, "0", fixed_link[0]);
 	} else {
 		phy = of_find_node_by_phandle(*ph);
 
@@ -256,7 +256,7 @@ static int gfar_of_init(struct net_device *dev)
 		of_node_put(mdio);
 
 		gfar_mdio_bus_name(bus_name, mdio);
-		snprintf(priv->phy_bus_id, BUS_ID_SIZE, "%s:%02x",
+		snprintf(priv->phy_bus_id, sizeof(priv->phy_bus_id), "%s:%02x",
 				bus_name, *id);
 	}