fix return success response. Others.

Add a String method to the path location in e2e request.

go/cs/reservation/e2e/request.go

@@ -127,6 +127,19 @@ const (
 	Destination
 )
 
+func (l PathLocation) String() string {
+	switch l {
+	case Source:
+		return "source"
+	case Transit:
+		return "trantit"
+	case Destination:
+		return "destination"
+	}
+	return "unknown path location"
+}
+
+// Location returns the location of this node in the path of the request.
 func (r *SetupReq) Location() PathLocation {
 	switch len(r.AllocationTrail) {
 	case 0:

go/cs/reservationstore/store.go

@@ -419,8 +419,9 @@ func (s *Store) AdmitE2EReservation(ctx context.Context, request e2e.SetupReques
 
 	var msg base.MessageWithPath
 	if req.Location() == e2e.Destination {
+		asAResponse := failedResponse.(*e2e.ResponseSetupFailure)
 		msg = &e2e.ResponseSetupSuccess{
-			Response: failedResponse.(*e2e.ResponseSetupFailure).Response,
+			Response: *morphE2EResponseToSuccess(&asAResponse.Response),
 			Token:    *index.Token,
 		}
 	} else {