directfb: remove useless cairo_surface cleanup
directfb: remove useless cairo_surface cleanup

This is done by gdk_directfb_cairo_surface_destroy via cairo_surface_set_user_data.

Signed-off-by: Lionel Landwerlin <c05e47e57584a5194aa13fa9b87ac49f6ecd5024@gmail.com>

Distrotech/gtk,Unity-Technologies/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk,johne53/MB3Gtk-2,Distrotech/gtk,Unity-Technologies/gtk,johne53/MB3Gtk-2,Distrotech/gtk,Distrotech/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk,Distrotech/gtk,johne53/MB3Gtk-2,Unity-Technologies/gtk