Cleanup: remove redundant checks which have already been tested

Note that these changes are limited simple cases as these kinds of
changes could allow for errors when refactoring code when the known
state is not so obvious.

source/blender/nodes/composite/nodes/node_composite_cryptomatte.cc

@@ -52,7 +52,7 @@ static blender::bke::cryptomatte::CryptomatteSessionPtr cryptomatte_init_from_no
   BLI_assert(GS(scene->id.name) == ID_SCE);
 
   if (use_meta_data) {
-    Render *render = (scene) ? RE_GetSceneRender(scene) : nullptr;
+    Render *render = RE_GetSceneRender(scene);
     RenderResult *render_result = render ? RE_AcquireResultRead(render) : nullptr;
     if (render_result) {
       session = blender::bke::cryptomatte::CryptomatteSessionPtr(