lan78xx: remove redundant initialization of pointer 'phydev'

Pointer phydev is initialized and this value is never read, phydev
is immediately updated to a new value, hence this initialization
is redundant and can be removed

Cleans up clang warning:
drivers/net/usb/lan78xx.c:2009:21: warning: Value stored to 'phydev'
during its initialization is never read
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/usb/lan78xx.c

@@ -2006,7 +2006,7 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
 {
 	int ret;
 	u32 mii_adv;
-	struct phy_device *phydev = dev->net->phydev;
+	struct phy_device *phydev;
 
 	phydev = phy_find_first(dev->mdiobus);
 	if (!phydev) {