r8169: remove netif_napi_del in probe error path

netif_napi_del is called implicitely by free_netdev, therefore we
don't have to do it explicitely.

When the probe error path is reached, the net_device isn't
registered yet. Therefore reordering the call to netif_napi_del
shouldn't cause any issues.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>