[ofw] [PATCH 3/9] events: allow callbacks per CQ, QP, or SRQ

[Sean Hefty]

>Are the event_handlers are always installed ?

Yes - all of the users of this interface provide event_handlers.  It's not an optional parameter to the API.

>[You removed all NULL-checking]
>What if user is not interested in asynchronic events at all ?

They can ignore the event.  But both ibal and winverbs act on the events. 

>What if user hadn't defined CQ completion callback, but mistakenly posts
>sends with completion flag ?

We trust the clients not to do this, the same way that we trust them to provide valid pointers.  This sort of mistake is
not correctable at run time and shows that there's an error in the user's logic.  They could just as easily mistakenly
not set the callback, and wanted the completion, which is now hidden from them.

- Sean