floating_drag_window: return on DRAG_REVERT
floating_drag_window: return on DRAG_REVERT

Right now tree_render() is called twice on DRAG_REVERT since
floating_reposition calls it.
Also, on DRAG_REVERT the scratchpad state shouldn't change since the
user canceled the action.

i3/i3,stapelberg/i3,Airblader/i3-original,i3/i3,Airblader/i3-original,Airblader/i3,Airblader/i3-original,stapelberg/i3,i3/i3,Airblader/i3,stapelberg/i3,Airblader/i3-original,Airblader/i3,Airblader/i3-original,Airblader/i3,stapelberg/i3,i3/i3