[SPARK-9248] [SPARKR] Closing curly-braces should always be on their own line

### JIRA
[[SPARK-9248] Closing curly-braces should always be on their own line - ASF JIRA](https://issues.apache.org/jira/browse/SPARK-9248)

## The result of `dev/lint-r`
[The result of `dev/lint-r` for SPARK-9248 at the revistion:6175d6cf](https://gist.github.com/yu-iskw/96cadcea4ce664c41f81)

Author: Yuu ISHIKAWA <yuu.ishikawa@gmail.com>

Closes #7795 from yu-iskw/SPARK-9248 and squashes the following commits:

c8eccd3 [Yuu ISHIKAWA] [SPARK-9248][SparkR] Closing curly-braces should always be on their own line