The flu has forced an early end to Billy Bob Thornton’s musical tour of Canada, his publicist said Saturday. The news was reportedly greeted with loud applause at a Friday night show in Montreal after Thornton called Canadian concert-goers “mashed potatoes with no gravy” in a radio interview Wednesday. The Boxmasters’ final Canadian dates — in Montreal and London, Ontario — were canceled because “one of the band members and several of the crew have the flu,” said Thornton publicist Arnold Robinson