IB/ipath: Fix CQ flushing when QP is modified to error state

If a receive work request has been removed from the queue but has not
had a CQ entry generated for it and the QP is modified to the error
state, the completion entry generated is incorrect.  This patch fixes
the problem.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>