Blender Git Loki

Fix T74782: WorkBench TAA Artifacts During Painting/Drawing

When the TAA is finished the screen can still be redrawn by other
operations without the TAA needs to be reset.
If that happened the TAA did add a blank sample to the result.

This patch will add an early exit in the case TAA was finished. Note
that there are still some cases still not working. The overlay engine
can in certain circumstances draw directly into the default_fb what can
lead to render artifacts.