Update Generic.Files.xml

The default for LineLength seems to be 80/100 instead of 80/120. I recently added a scrutinizer file to one of my projects with just this line:

    <rule ref="Generic.Files.LineLength"/>

assuming that it would use the 120 absolute limit shown in the UI. But instead it would report violations at 100 already.

Compare with https://github.com/squizlabs/PHP_CodeSniffer/blob/master/CodeSniffer/Standards/Generic/Sniffs/Files/LineLengthSniff.php