[animation] Fix variable use
[animation] Fix variable use

Instead of using the proper typed variables we were overwriting
the gpointer for the Interval's final value.

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