sw: avoid temporary object creation to build GraphicPrimitive2D
sw: avoid temporary object creation to build GraphicPrimitive2D

As drawinglayer::primitive2d::GraphicPrimitive2D constructor expects a
GraphicObject ref, we can simply pass in rGrfObj instead of building a
(implicit) temp GraphicObjet using the GetGraphic() result.

Change-Id: I8c54f20804390c773fdf9406f534787ce7143e84
Reviewed-on: https://gerrit.libreoffice.org/14390
Tested-by: Michael Stahl <eef8671db506f9731c0438a7613853b6391ca841@redhat.com>
Reviewed-by: Michael Stahl <eef8671db506f9731c0438a7613853b6391ca841@redhat.com>

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core