VIA http://uk.eonline.com/ REPORTS Chris Brown just showed up, end of story. That’s what the R&B star implied anyway in response to an accusation that Will.i.am ripped off another song to make his track “Let’s Go,” which features Brown (and isn’t to be confused with the Calvin Harris tune featuring Ne-Yo). “I don’t even know who mat zo Or arty is? I ain’t got s–t to do wit if ur mad or not. Someone asked for a feature on a record and I did it,” Brown wrote in a tweet that has since been deleted, though it was caught for posterity in a screengrab by the Huffington Post. Still online are the following possibly related Brown tweets: “I don’t listen…