data inconsistency is reported when query with for update clause

[wjhuang2016]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

CREATE TABLE `ccf0ed15` (
  `f9e69bc7` bigint(20) DEFAULT '1112823069779687543',
  `d33b6c1b` decimal(41,16) DEFAULT '5518242590970756357909774.8550717763805231',
  `56231d4d` set('35','pi','dqurb','yita3','kczu','a','t8','4d','bh4qs','lk9a','75k') DEFAULT '35,pi,kczu,a,t8,4d,bh4qs,75k',
  UNIQUE KEY `d2200701` (`d33b6c1b`,`f9e69bc7`),
  UNIQUE KEY `9efc4c6b` (`f9e69bc7`),
  KEY `8a590049` (`56231d4d`)
) ENGINE=InnoDB DEFAULT CHARSET=gbk COLLATE=gbk_chinese_ci COMMENT='46791f67'
PARTITION BY HASH (`f9e69bc7`) PARTITIONS 5;
INSERT INTO `ccf0ed15` VALUES
(-7801043551743108407,4626.1410000000000000,'yita3'),
(5755921862464422919,0.4787000000000000,'dqurb'),
(6818225316668061803,5800.0000000000000000,'35'),
(1112823069779687543,5518242590970756357909774.8550717763805231,'dqurb'),
(3823184061824785364,31.7690000000000000,'bh4qs'),
(6741424187029746717,7264.0000000000000000,'pi'),
(7056863346120328265,17.5560000000000000,'dqurb'),
(5552107058771389209,7444.4900000000000000,'a');

select  /*+ use_index_merge( `ccf0ed15` ) */   `ccf0ed15`.`56231d4d` as r0 from `ccf0ed15`    order by r0 limit 82 for update;

2. What did you expect to see? (Required)

No error

3. What did you see instead (Required)

mysql> select  /*+ use_index_merge( `ccf0ed15` ) */   `ccf0ed15`.`56231d4d` as r0 from `ccf0ed15`    order by r0 limit 82 for update;
ERROR 8133 (HY000): data inconsistency in table: ccf0ed15, index: 8a590049, index-count:2 != record-count:1

4. What is your TiDB version? (Required)

master

[Defined2014]

I think it only happens when static-prune with set(The encode type with set from tikv will equals to EncodeType::TypeDefault), so change it to moderate.