r8169: switch to device-managed functions in probe

Simplify probe error path and remove callback by using device-managed
functions.

rtl_disable_msi isn't needed any longer because the release callback
of pcim_enable_device does this implicitely.

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