Avoid nil dereference on failed getNodeCost

costmodel/costmodel.go

@@ -84,7 +84,8 @@ func ComputeCostData(cli prometheusClient.Client, clientset *kubernetes.Clientse
 
 	nodes, err := getNodeCost(clientset, cloud)
 	if err != nil {
-		log.Printf("Warning, no cost model available: " + err.Error())
+		log.Printf("Warning, no Node cost model available: " + err.Error())
+		return nil, err
 	}
 
 	podlist, err := clientset.CoreV1().Pods("").List(metav1.ListOptions{})