Detectives in the Bronx are on the hunt for the roommate of a man whose rotting body was found inside a home, with a knife still lodged in the corpse, on Wednesday afternoon. Police sources said the grim discovery was made at 1:44 p.m. on June 3 inside a two-story residence on the 1000 block of Longfellow Ave. in Longwood. Officers from the 41st Precinct were called to the location after another resident reported smelling a foul odor for several…