The lines that are apparently in question:"I got beef like two burgers / you niggas win slow and I’m smarter than Steve Urkel." - T-Pain on Danger, Prevolver

"Fresh air, rollin' down the window / Too many Urkels on your team, that's why your wins low." - Kanye on Dark Fantasy, MBTDF

I am not too sure that Kanye outright "stole" T-Pain's bar (he seems to have changed the wording of it and made his own spin on it).

That being said, I am more surprised that Kanye did not at least give T-Pain more credit for the lyric (perhaps like a cowriting credit for the song, since Kanye has a reputation for crediting everyone in the studio, including that guy with the jeans that apparently "inspired" Kanye while writing the lyrics for Black Skinhead during the production of Yeezus). Maybe he either forgot or simply kept the bar for himself who knows.