[ofw] WinVerbs CQ events

[Sean Hefty]

>I expect either 2 CQ events in the receive side or ibv_poll_cq(..)
>should return 2 WCs.

I believe this will only be true if you rearm the CQ (ibv_req_notify_cq) before
calling ibv_poll_cq for the first time.

Does anyone know if the HCA will generate an event if the CQ is rearmed after a
WC has been added, but not polled?  (This is separate from what the IB spec
indicates, but I thought how the HCA worked on linux.)  If so, then there could
be a missing event here.