jsonpath: add err check for jsonValue Iterator retrieval

There are 2 types that can return ObjectJSONType as the type: json.jsonObject
or json.jsonEncoded. The latter can return not-nil error in their implementation
of ObjectIter(). This commit is to add error check for this case.

Release note: None

Author: ZhouXing19

pkg/util/jsonpath/eval/eval.go

@@ -267,7 +267,10 @@ func (ctx *jsonpathCtx) executeAnyItem(
 			}
 		}
 	case json.ObjectJSONType:
-		iter, _ := jsonValue.ObjectIter()
+		iter, err := jsonValue.ObjectIter()
+		if err != nil {
+			return nil, errors.Wrapf(err, "getting iterator for json object")
+		}
 		for iter.Next() {
 			if err := processItem(iter.Value()); err != nil {
 				return nil, err