fix NULL pointer in handle_eeh_events

[Olaf Hering]

 On Mon, Feb 27, Linas Vepstas wrote:

> > but ethtool -t still doesnt work right.
> 
> I'll look at this.

Reverting e100.c back to 2.6.15 status fixes it, but maybe it just does
not cover the error paths in EEH.