Problem:
It will return a result although we use wrong ak/sk/bucket name, such as:
```sql
mysql> select * from demo.student
-> into outfile "s3://xxxx/exp_"
-> format as csv
-> properties(
-> "s3.endpoint" = "https://cos.ap-beijing.myqcloud.com",
-> "s3.region" = "ap-beijing",
-> "s3.access_key"= "xxx",
-> "s3.secret_key" = "yyyy"
-> );
+------------+-----------+----------+----------------------------------------------------------------------------------------------------+
| FileNumber | TotalRows | FileSize | URL |
+------------+-----------+----------+----------------------------------------------------------------------------------------------------+
| 1 | 3 | 26 | s3://xxxx/exp_2ae166e2981d4c08-b577290f93aa82ba_ |
+------------+-----------+----------+----------------------------------------------------------------------------------------------------+
1 row in set (0.15 sec)
```
The reason for this is that we did not catch the error returned by `close()` phase.
f32efe5758