[NbtkWidget] remove unused variable from nbtk_stylable_iface_init
[NbtkWidget] remove unused variable from nbtk_stylable_iface_init

jonnylamb/mx,clutter-project/mx,pwithnall/mx,clutter-project/mx,pwithnall/mx,jonnylamb/mx,jonnylamb/mx,clutter-project/mx,clutter-project/mx,pwithnall/mx,jonnylamb/mx,pwithnall/mx