Otherwise it's not easy to see which frame position was invalidated in
SwFrameAreaDefinition::setFrameAreaPositionValid() in a SAL_DEBUG()
statement.

Change-Id: I5771a81b98524bbce6557653a1a366e7a91c583e
Reviewed-on: https://gerrit.libreoffice.org/60443Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins