A popular on-site promotion at Rich Harvest Farms celebrated the British Open winner’s hairstyle, then Smith won for the first time since joining LIV Golf. SUGAR GROVE, Ill. — While Cam Smith traversed the Rich Harvest Farms course in search of his first LIV Golf Invitational Series victory, a steady stream of customers visited a booth in the fan village set up in his honor. The reigning British Open champion from Australia who sports an impressive mullet was the subject of a promotion in which spectators at the tournament could get the same treatment. There was no fee, and those…