[Doris On ES] Incorrect result when `enable_docvalue_scan`

[wuyunfeng]

when use enable_docvalue_scan, such as :

CREATE EXTERNAL TABLE `doe` (
  `id` bigint(20) NULL COMMENT "",
  `city` varchar(20) NULL COMMENT "",
  `opin_type` varchar(20) NULL COMMENT ""
) ENGINE=ELASTICSEARCH
COMMENT "ELASTICSEARCH"
PROPERTIES (
"hosts" = "http://127.0.0.1:8200",
"user" = "root",
"password" = "",
"index" = "doe2",
"type" = "doc",
"transport" = "http",
"enable_docvalue_scan" = "true",
"enable_keyword_sniff" = "true"
); 

just index a few documents , and set batch_size = [1 ... n], the result is inconsistent, batch_size - N / batch_size NULL per shard would be added to the result because of the wrong usage of total hits.