reorder code in ipt_mgr.rs

// TODO HSS: Combine this block with the other impl IptManager<R, M>
// We probably want to make sure this whole file is in a sensible order.
impl<R: Runtime, M: Mockable<R>> IptManager<R, M> {

Code changes have resulted in a file that is not necessarily in a logical order. Let's not do that movement right now before I go away.