texture2D() is still available, but not in the geometry stage, so
better be consistent everywhere.

Change-Id: I86bf1921713bcbf32946190525401bfcc633a69f
Reviewed-on: https://gerrit.libreoffice.org/22468Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>