[SNC-16922] Another fix for path validator (sonic-net#66)

* Path validator fix for union and identity ref cases

* Go format fix

* Add Balachandar's patch to fix path validator issue

translib/path_validator.go

@@ -107,6 +107,9 @@ func (pv *pathValidator) getYangSchema() (*yang.Entry, error) {
 func (pv *pathValidator) getStructField(nodeName string) *reflect.StructField {
 	var sField *reflect.StructField
 	sval := reflect.ValueOf(pv.sValIntf).Elem()
+	if sval.Kind() != reflect.Struct {
+		return nil
+	}
 	stype := sval.Type()
 	for i := 0; i < sval.NumField(); i++ {
 		fType := stype.Field(i)