routing/route+multi: remove redundant TotalFees field

Instead get it on demand using method TotalFees().

lnrpc/routerrpc/router_backend.go

@@ -185,8 +185,8 @@ func calculateFeeLimit(feeLimit *lnrpc.FeeLimit,
 func (r *RouterBackend) MarshallRoute(route *route.Route) *lnrpc.Route {
 	resp := &lnrpc.Route{
 		TotalTimeLock: route.TotalTimeLock,
-		TotalFees:     int64(route.TotalFees.ToSatoshis()),
-		TotalFeesMsat: int64(route.TotalFees),
+		TotalFees:     int64(route.TotalFees().ToSatoshis()),
+		TotalFeesMsat: int64(route.TotalFees()),
 		TotalAmt:      int64(route.TotalAmount.ToSatoshis()),
 		TotalAmtMsat:  int64(route.TotalAmount),
 		Hops:          make([]*lnrpc.Hop, len(route.Hops)),

lnrpc/routerrpc/router_backend_test.go

@@ -55,8 +55,6 @@ func TestQueryRoutes(t *testing.T) {
 		}},
 	}
 
-	rt := &route.Route{}
-
 	findRoute := func(source, target route.Vertex,
 		amt lnwire.MilliSatoshi, restrictions *routing.RestrictParams,
 		finalExpiry ...uint16) (*route.Route, error) {
@@ -95,7 +93,8 @@ func TestQueryRoutes(t *testing.T) {
 			t.Fatal("unexpected ignored node")
 		}
 
-		return rt, nil
+		hops := []*route.Hop{&route.Hop{}}
+		return route.NewRouteFromHops(amt, 144, source, hops)
 	}
 
 	backend := &RouterBackend{

lnrpc/routerrpc/router_server.go

@@ -269,7 +269,7 @@ func (s *Server) EstimateRouteFee(ctx context.Context,
 	}
 
 	return &RouteFeeResponse{
-		RoutingFeeMsat: int64(route.TotalFees),
+		RoutingFeeMsat: int64(route.TotalFees()),
 		TimeLockDelay:  int64(route.TotalTimeLock),
 	}, nil
 }