to reduce code clutter like
    pLbSelect->GetEntryData(pLbSelect->GetSelectEntryPos())
since this is a fairly frequent operation.

Change-Id: I41daf30fdeda2442ad1ac829e12f553233bae184
Reviewed-on: https://gerrit.libreoffice.org/14472Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>