This also inlines LineListBox::ImplInit(). Note that m_vLineList
never contains nullptr.

Change-Id: Ia4798943fbb53e1720d51faff7643e46d2cd2585
Reviewed-on: https://gerrit.libreoffice.org/47046Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>