The shop that kept the Loop smoking for more than four decades closed its doors yesterday — blaming falling revenue and a landlord's demands.Jessica Bueler, whose father founded HSB Tobacconist (6364 Delmar Boulevard, University City) in 1972 and moved it to the Loop one year later, says she had been under a payment plan with landlord Joe Edwards. Trolley construction hurt foot traffic on the street, she says, and revenue was down considerably.…