Checkstyle reporter sometimes outputs unused variable warnings, even what that option is not used

[Lugribossk]

1. Set up the jshint task options without "unused": true (or explicitly set it to false), a single input file, and the "checkstyle" reporter.
2. Run the task and notice that the Checkstyle XML has no unused variable warnings in it.
3. Add a second input file and run the task again.
4. Notice that the XML now has unused variable warnings, but only from the second file.

Example setup: https://gist.github.com/Lugribossk/5709321

This is with Grunt v0.4.1 and grunt-contrib-jshint v0.6.0.

[shama]

This plugin is a fairly thin wrapper to jshint and the checkstyle reporter is built into jshint. Could you open an issue over on https://github.com/jshint/jshint/issues for this instead? Thank you!