net: phy: fix memory leak in device-create error path

A recent commit introduced a late error path in phy_device_create()
which fails to release the device name allocated by dev_set_name().

Fixes: 13d0ab67 ("net: phy: check return code when requesting PHY driver module")
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>