## What changes were proposed in this pull request?
The lint failure bugged me:
```R
R/SQLContext.R:715:97: style: Trailing whitespace is superfluous.
#' file-based streaming data source. \code{timeZone} to indicate a timezone to be used to
^
tests/fulltests/test_streaming.R:239:45: style: Commas should always have a space after.
expect_equal(times[order(times$eventTime),][1, 2], 2)
^
lintr checks failed.
```
and I actually saw https://amplab.cs.berkeley.edu/jenkins/job/spark-master-test-sbt-hadoop-2.6-ubuntu-test/500/console too. If I understood correctly, there is a try about moving to Unbuntu one.
## How was this patch tested?
Manually tested by `./dev/lint-r`:
```
...
lintr checks passed.
```
Author: hyukjinkwon <gurwls223@apache.org>
Closes#20879 from HyukjinKwon/minor-r-lint.
92e952557d