Blender Git Loki

Fix #32205: Holdout shader + transparent background stays black with Alpha = 1

It was read of initialized memory around holdout_weight in cases when
holdout material is used. Seems that it should be assigned to result
of shader_holdout_eval here.

If Brecht could double check this it'll be great.

This could potentially fix #32224: Holdout Error with CUDA Cycles Render