r8169: issue request_irq after the private data are completely initialized

The irq handler schedules a NAPI poll request unconditionally as soon as
the status register is not clean. It has been there - and wrong - for
ages but a recent timing change made it apparently easier to trigger.

Adrian Bunk:
backported to 2.6.16

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>