[SPARK-16985] Change dataFormat from yyyyMMddHHmm to yyyyMMddHHmmss

## What changes were proposed in this pull request?

In our cluster, sometimes the sql output maybe overrided. When I submit some sql, all insert into the same table, and the sql will cost less one minute, here is the detail,
1 sql1, 11:03 insert into table.
2 sql2, 11:04:11 insert into table.
3 sql3, 11:04:48 insert into table.
4 sql4, 11:05 insert into table.
5 sql5, 11:06 insert into table.
The sql3's output file will override the sql2's output file. here is the log:
```
16/05/04 11:04:11 INFO hive.SparkHiveHadoopWriter: XXfinalPath=hdfs://tl-sng-gdt-nn-tdw.tencent-distribute.com:54310/tmp/assorz/tdw-tdwadmin/20160504/04559505496526517_-1_1204544348/10000/_tmp.p_20160428/attempt_201605041104_0001_m_000000_1

16/05/04 11:04:48 INFO hive.SparkHiveHadoopWriter: XXfinalPath=hdfs://tl-sng-gdt-nn-tdw.tencent-distribute.com:54310/tmp/assorz/tdw-tdwadmin/20160504/04559505496526517_-1_212180468/10000/_tmp.p_20160428/attempt_201605041104_0001_m_000000_1

```

The reason is the output file use SimpleDateFormat("yyyyMMddHHmm"), if two sql insert into the same table in the same minute, the output will be overrite. I think we should change dateFormat to "yyyyMMddHHmmss", in our cluster, we can't finished a sql in one second.

## How was this patch tested?

(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)

(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Author: hongshen <shenh062326@126.com>

Closes #14574 from shenh062326/SPARK-16985.