Fix PathBuildingHop visibility

Author: jurvis

lightning/src/routing/router.rs

@@ -424,7 +424,7 @@ impl<'a> CandidateRouteHop<'a> {
 /// Fee values should be updated only in the context of the whole path, see update_value_and_recompute_fees.
 /// These fee values are useful to choose hops as we traverse the graph "payee-to-payer".
 #[derive(Clone)]
-pub struct PathBuildingHop<'a> {
+struct PathBuildingHop<'a> {
 	// Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
 	// is a larger refactor and will require careful performance analysis.
 	node_id: NodeId,