fdo#43157 - Clean up OSL_ASSERT, DBG_ASSERT

Changed OSL_ASSERT with SAL_WARN_IF

Change-Id: Ie81eeb51f6978162abd372f7e9910344a2baaccd
Reviewed-on: https://gerrit.libreoffice.org/9401
Reviewed-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>
Tested-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>