gdk: master clock: fix incorrect symbol use
gdk: master clock: fix incorrect symbol use

https://bugzilla.gnome.org/show_bug.cgi?id=754134

jigpu/clutter,jigpu/clutter,Distrotech/clutter,Distrotech/clutter,Distrotech/clutter,jigpu/clutter,jigpu/clutter,GNOME/clutter,GNOME/clutter,GNOME/clutter,Distrotech/clutter,jigpu/clutter,GNOME/clutter,GNOME/clutter,jigpu/clutter,Distrotech/clutter,Distrotech/clutter