This is actually cultural racism from FA. They totally disregard the context, they totally disregard that this is a widely used term used in Uruguay, and it's used as a friendly term. Like "bro". I bet Cavani also is called negrito by friends in Uruguay. It's NOT the same as the Evra incident, where Suarez said "because you're negrito", where he clearly claimed that he kicked him because Evra is black.
FA should climb down from their racism-pedestal and take to account that other cultures might have other languages and terms than English. We can't translate everything, word for word, and conclude "this is bad, this is good". I assume Cavani will get a game or two on the sideline, and the FA are some pricks not deciding this while he was injured anyway. This is not how to kick racism out of football. This is just bullshit.