compositor: Don't schedule repaint from weston_surface_update_transform()

compositor: Don't schedule repaint from weston_surface_update_transform()

weston_surface_update_transform() is typically called as part of the
repaint cycle so don't schedule a repaint here.  There are still a couple
of places where we call weston_surface_update_transform() manually, but
they don't rely on the repaint being scheduled.