By JOE REEDY, Associated Press Netflix is planning to provide plenty of gifts for viewers of its two Christmas Day games, including Mariah Carey kicking it all off with a taped performance of “All I Want for Christmas is You.” Yet, Netflix executive Brandon Riegg realizes it all amounts to a lump of coal if there are streaming problems. Riegg, vice president of nonfiction series and sports, has had to answer plenty of questions about the streaming giant’s readiness for the influx of viewers on what could be its biggest day ever, especially after streaming problems during the Nov.