[ClutterActor] Fix check for zero opacity when being painted from a clone
[ClutterActor] Fix check for zero opacity when being painted from a clone

Clutter short-circuits painting when an actor's opacity is
zero. However if the actor is being painted from a ClutterClone then
it will be painted using the clone's opacity instead so the test was
broken.

heysion/clutter-clone,spatulasnout/clutter,Distrotech/clutter,rkudiyarov/clutter_osx,Distrotech/clutter,Distrotech/clutter,jigpu/clutter,djdeath/clutter-multithreaded,djdeath/clutter,Distrotech/clutter,kerrickstaley/clutter-vala,ebassi/clutter,collects/clutter,ebassi/clutter,djdeath/clutter,djdeath/clutter-android,spatulasnout/clutter,tardyp/clutter,jigpu/clutter,GNOME/clutter,djdeath/clutter,djdeath/clutter-android,djdeath/clutter-multithreaded,djdeath/clutter,heysion/clutter-clone,jigpu/clutter,nobled/clutter,Distrotech/clutter,GNOME/clutter,djdeath/clutter-android,ebassi/clutter,collects/clutter,djdeath/clutter-android,kerrickstaley/clutter-vala,heysion/clutter-clone,kerrickstaley/clutter-vala,nobled/clutter,collects/clutter,dlespiau/clutter,dlespiau/clutter,rkudiyarov/clutter_osx,rkudiyarov/clutter_osx,kerrickstaley/clutter-vala,GNOME/clutter,collects/clutter,heysion/clutter-clone,nobled/clutter,dlespiau/clutter,Distrotech/clutter,djdeath/clutter-android,rkudiyarov/clutter_osx,spatulasnout/clutter,jigpu/clutter,heysion/clutter-clone,GNOME/clutter,tardyp/clutter,ebassi/clutter,jigpu/clutter,djdeath/clutter-multithreaded,ebassi/clutter,collects/clutter,spatulasnout/clutter,GNOME/clutter,djdeath/clutter,djdeath/clutter-multithreaded,spatulasnout/clutter,jigpu/clutter,djdeath/clutter,tardyp/clutter