memory cancelled query may end with executed sucess flag in slow log

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

mock code


and create table a table named as tai as above, insert 1 row, and select * from tai;

### 2. What did you expect to see? (Required)
slow log item: select * from tai should not be tagged as success

### 3. What did you see instead (Required)


### 4. What is your TiDB version? (Required)

master