VOL-1797 - fix helm lint issues

Change-Id: I74ccff1f7f431e05fc3963d0707382f478a010f0
diff --git a/voltha-adapter-openonu/templates/adapters-openolt.yaml b/voltha-adapter-openonu/templates/adapters-openolt.yaml
index d4afdc7..9447d90 100644
--- a/voltha-adapter-openonu/templates/adapters-openolt.yaml
+++ b/voltha-adapter-openonu/templates/adapters-openolt.yaml
@@ -37,7 +37,7 @@
     spec:
       containers:
         - name: adapter-open-onu
-          image: {{ tpl .Values.images.adapter_open_onu.registry . }}{{ tpl .Values.images.adapter_open_onu.repository . }}:{{ tpl .Values.images.adapter_open_onu.tag . }}
+          image: {{ tpl .Values.images.adapter_open_onu.registry . }}{{ tpl .Values.images.adapter_open_onu.repository . }}:{{ tpl ( tpl .Values.images.adapter_open_onu.tag . ) . }}
           imagePullPolicy: {{ tpl .Values.images.adapter_open_onu.pullPolicy . }}
           args:
             - "/voltha/adapters/brcm_openomci_onu/main.py"