Bills Mafia is officially down one head coach. The Bills fired Sean McDermott on Monday after nine seasons, the final of which ended Saturday with an overtime divisional round playoff loss to the Broncos in Denver. McDermott finishes his time in Buffalo with a regular-season record of 98-50 and a postseason mark of 8-8. The Bills will keep GM Brandon Beane and he will lead the coach for the next head coach, NFL Network reported. Of course, Saturday’s crushing 33-30 loss to the Broncos in extra