fix(server): shutdown logging fixes

pkg/cmd/grafana-server/main.go

@@ -107,7 +107,7 @@ func listenToSystemSignals(server models.GrafanaServer) {
 
 	select {
 	case sig := <-signalChan:
-		server.Shutdown(0, fmt.Sprintf("system signal=%s", sig))
+		server.Shutdown(0, fmt.Sprintf("system signal: %s", sig))
 	case code = <-exitChan:
 		server.Shutdown(code, "startup error")
 	}

pkg/cmd/grafana-server/server.go

@@ -103,13 +103,12 @@ func (g *GrafanaServerImpl) startHttpServer() {
 }
 
 func (g *GrafanaServerImpl) Shutdown(code int, reason string) {
-	log.Info("Shutting down", "code", code, "reason", reason)
+	g.log.Info("Shutting down", "code", code, "reason", reason)
 
 	g.shutdownFn()
 	err := g.childRoutines.Wait()
 
-	log.Info("Shutting down completed", "error", err)
-
+	g.log.Info("Shutting down completed", "reason", err)
 	log.Close()
 	os.Exit(code)
 }