During OpenMPI scale up testing, we observe rdma_connect
failures if ports are reused on multiple connections.
This is because the Control Queue-Pair (CQP) command to add
the reused port to Accelerated Port Bit VectorTable (APBVT)
fails as there already exists an entry.

Check for duplicate port before invoking the CQP command
to add APBVT entry and delete the entry only if the port
is not in use.
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>