multi: add shutdown logs in subservers

This commit adds a simple shutdown to every subserver to assist
debugging.

htlcswitch/hop/iterator.go

@@ -137,6 +137,9 @@ func (p *OnionProcessor) Start() error {
 
 // Stop shutsdown the onion processor's sphinx router.
 func (p *OnionProcessor) Stop() error {
+
+	log.Info("Onion processor shutting down")
+
 	p.router.Stop()
 	return nil
 }

htlcswitch/htlcnotifier.go

@@ -91,6 +91,7 @@ func (h *HtlcNotifier) Start() error {
 func (h *HtlcNotifier) Stop() error {
 	var err error
 	h.stopped.Do(func() {
+		log.Info("HtlcNotifier shutting down")
 		if err = h.ntfnServer.Stop(); err != nil {
 			log.Warnf("error stopping htlc notifier: %v", err)
 		}

htlcswitch/switch.go

@@ -1942,7 +1942,7 @@ func (s *Switch) Stop() error {
 		return errors.New("htlc switch already shutdown")
 	}
 
-	log.Infof("HTLC Switch shutting down")
+	log.Info("HTLC Switch shutting down")
 
 	close(s.quit)