IB/qib: Generate completion callback on errors

According to IBTA vol. 1, C11-30.1.1, a notification callback is
invoked if the CQ is armed for the next solicited completion event or
an error completion.  The error case wasn't being generated correctly.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>