aeroflex/greth: fix warning about unused variable

Fix following warning:
aeroflex/greth.c:1326:11: warning: unused variable 'phy' [-Wunused-variable]

The variable was unused - remove it.
It looks like this warning has been there forever - was found by an
allyesconfig build of sparc32.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Kristoffer Glembo <kristoffer@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/aeroflex/greth.c

@@ -1323,7 +1323,7 @@ static inline int phy_aneg_done(struct phy_device *phydev)
 
 static int greth_mdio_init(struct greth_private *greth)
 {
-	int ret, phy;
+	int ret;
 	unsigned long timeout;
 
 	greth->mdio = mdiobus_alloc();