frame: Add missing return value to clutter_gst_frame_new
frame: Add missing return value to clutter_gst_frame_new

Fix clutter_gst_frame_new to really return a new frame.

https://bugzilla.gnome.org/show_bug.cgi?id=696127

GNOME/clutter-gst,GNOME/clutter-gst,GNOME/clutter-gst,GNOME/clutter-gst