There is no record of Cobain having ever said this, and it's unlikely the singer would have had much of an opinion about Donald Trump's political chances.
Although the businessman had periodically mused about a political career, it would be many years before he mounted a serious campaign for office. Trump also suffered a string of high-profile business failures in the early '90s, so the characterization of him as a successful tycoon not beholden to anyone is at odds with his business record at the time.
And if all that weren't enough, this particular image also misspells Kurt Cobain's name. 😧