add tolerations to allow node-exporter running on all nodes

manifests/node-exporter/node-exporter-daemonset.yaml

@@ -35,6 +35,9 @@ spec:
         - name: sys
           readOnly: true
           mountPath: /host/sys
+      tolerations:
+        - effect: NoSchedule
+          operator: Exists
       volumes:
       - name: proc
         hostPath: