stmmac: fix phy naming inconsistency

After commit "db8857b stmmac: use an unique MDIO bus name" my
device stopped being probed because two different names were being
used in different places. This fixes the inconsistency.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Florian Fainelli <florian@openwrt.org>
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c

@@ -154,7 +154,7 @@ int stmmac_mdio_register(struct net_device *ndev)
 	else
 		irqlist = priv->mii_irq;
 
-	new_bus->name = "STMMAC MII Bus";
+	new_bus->name = "stmmac";
 	new_bus->read = &stmmac_mdio_read;
 	new_bus->write = &stmmac_mdio_write;
 	new_bus->reset = &stmmac_mdio_reset;