Almost four months after Chris Noth was fired from “The Equalizer” over multiple allegations of sexual assault, his character finally suffered an unsanctimonious goodbye. In Sunday night’s episode of the CBS procedural, Robyn McCall (Queen Latifah) realizes that her mentor, William Bishop (Noth), has spent the last few months hunting for an explanation for why a plane went down, only to discover that the man behind the crash is her nemesis Mason Quinn (Chris Vance). As McCall races to stop Quinn from setting off another electromagnetic pulse and knocking another plane out of the sky, she finds…