dapl/ibal: delay QP transition until user disconnects

dapl/ibal: delay QP transition until user disconnects

The ibal provider calls ib_cm_drep in response to receiving
a dreq.  The result is that the user's QP is transitioned
through the error state, which fails any outstanding send
operations and flushes all receives.  The disconnect request
is then reported to the user.

Since a user can receive errors from the QP before they are
aware of a pending disconnect request, the application may
respond to the errors as, well, actual errors.  Fix this by
delaying the QP transition until the user responds to the
dreq.

This fixes an error with Intel MPI running over the ibal
dapl provider with a 'spawn' test.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>