[ofw] __cleanup_cep() oddity

[Sean Hefty]

>Seems like it is superfluous sanity check.

I was hoping that was the case, but I wasn't sure.  I added a print inside the
if statement and haven't seen it yet, but I'm only testing winverbs at the
moment.

>But it is better to set ASSERT and to return p_cep->ref_cnt.

I'll look at changing this.  I'm trying to debug a hang cleaning up CEPs, so
I've been checking locations where the CEP ref_cnt is adjusted.

- Sean