net: dsa: Improve subordinate PHY error message

It is not very informative to know the DSA master device when a
subordinate network device fails to get its PHY setup. Provide the
device name and capitalize PHY while we are it.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/dsa/slave.c

@@ -1795,7 +1795,8 @@ int dsa_slave_create(struct dsa_port *port)
 
 	ret = dsa_slave_phy_setup(slave_dev);
 	if (ret) {
-		netdev_err(master, "error %d setting up slave phy\n", ret);
+		netdev_err(master, "error %d setting up slave PHY for %s\n",
+			   ret, slave_dev->name);
 		goto out_gcells;
 	}