Fix access to value of var in gNMI Update

Description

Related Issue

Motivation and Context

How Has This Been Tested?

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Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

controller/nucleus/networkElementWatcher.go

@@ -247,11 +247,11 @@ func (n *NetworkElementWatcher) handleSubscribeResponseUpdate(resp *gpb.Subscrib
 
 		switch v := update.GetVal().GetValue().(type) {
 		case *gpb.TypedValue_StringVal:
-			pathsAndValues[pathString] = update.Val.GetStringVal()
+			pathsAndValues[pathString] = update.GetVal().GetStringVal()
 		case *gpb.TypedValue_JsonIetfVal:
 			pathsAndValues[pathString] = string(update.GetVal().GetJsonIetfVal())
 		case *gpb.TypedValue_UintVal:
-			pathsAndValues[pathString] = fmt.Sprintf("%d", update.Val.GetUintVal())
+			pathsAndValues[pathString] = fmt.Sprintf("%d", update.GetVal().GetUintVal())
 		default:
 			log.Errorf("The given value of type: %T, provided by a SubResponse from network element with ID: %s is not supported", v, subscriptionInfo.NetworkElementID)
 			return