r8169: revert 7da97ec9 (partly)

Various symptoms depending on the .config options:
- the card stops working after some (short) time
- the card does not work at all
- the card disappears (nothing in lspci/dmesg)

A real power-off is needed to recover the card.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>