LOS ANGELES—Frank Bonner, who played a brash salesman with an affection for polyester plaid suits on the TV comedy “WKRP in Cincinnati,” has died. He was 79. Bonner died Wednesday from complications of Lewy body dementia, said his daughter, Desiree Boers-Kort. The actor died at his home in Laguna Niguel, south of Los Angeles. He…