Netflix’s NFL debut kicked off on Christmas Day without a glitch. Mariah Carey opened Wednesday’s doubleheader with a taped performance of “All I Want for Christmas is You” before Patrick Mahomes, Travis Kelce and the two-time defending Super Bowl champion Kansas City Chiefs faced off against Russell Wilson, T.J. Watt and the Pittsburgh Steelers. The Houston Texans will host the Baltimore Ravens in the second game as the NFL showcases four of…