Body classes being improperly filtered

First of all, you should never echo in a filter function. Filters modify values, and are output (if necessary) by the originator of the filter. But since you're debugging here, I'm not too concerned with the echo statements themselves. It's the fact that the second echo statement isn't included in the debug conditional, causing it to echo an empty itemscope.

For people who use the `body_class()` function, this isn't a problem. But for people who use `get_body_class()` it definitely IS a problem, as it echoes the empty itemscope early. (Genesis 2.0, for instance)

This PR should fix that.