[SPARK-13870][SQL] Add scalastyle escaping correctly in CVSSuite.scala

## What changes were proposed in this pull request?

When initial creating `CVSSuite.scala` in SPARK-12833, there was a typo on `scalastyle:on`: `scalstyle:on`. So, it turns off ScalaStyle checking for the rest of the file mistakenly. So, it can not find a violation on the code of `SPARK-12668` added recently. This issue fixes the existing escaping correctly and adds a new escaping for `SPARK-12668` code like the following.

```scala
   test("test aliases sep and encoding for delimiter and charset") {
+    // scalastyle:off
     val cars = sqlContext
...
       .load(testFile(carsFile8859))
+    // scalastyle:on
```
This will prevent future potential problems, too.

## How was this patch tested?

Pass the Jenkins test.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11700 from dongjoon-hyun/SPARK-13870.