Resolve "Specific paths cant be requested, because the underlying device goStruct can't be filled."

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

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.

Closes #148 (closed)

nucleus/southbound.go

@@ -94,18 +94,18 @@ func unmarshal(schema *ytypes.Schema, bytes []byte, path *gpb.Path, goStruct ygo
 		return &errors.ErrInvalidTypeAssertion{}
 	}
 
-	// returns the node we want to fill with the data contained in 'bytes', using
-	// the specified 'path'.
+	// returns the node we want to fill with the data contained in 'bytes',
+	// using the specified 'path'.
 	createdNode, _, err := ytypes.GetOrCreateNode(schema.RootSchema(), validatedDeepCopy, path)
 	if err != nil {
 		return err
 	}
-	fieldStruct, ok := createdNode.(ygot.ValidatedGoStruct)
+	validatedCreatedNode, ok := createdNode.(ygot.ValidatedGoStruct)
 	if !ok {
 		return &errors.ErrInvalidTypeAssertion{}
 	}
 
-	if err := openconfig.Unmarshal(bytes, fieldStruct, opt...); err != nil {
+	if err := openconfig.Unmarshal(bytes, validatedCreatedNode, opt...); err != nil {
 		return err
 	}