The bold-face buyer of a second-floor apartment on Crosby Street in SoHo is Samuel L. Jackson, reports The Post’s Jennifer Gould Keil. We hear the seller, Wall Street dude Eric Gross, got such a kick out of Jackson buying his pad, he may have accepted the bid, despite it being a tad lower than a nonceleb offer of about $4.1 million. Let’s hope Jackson doesn’t have any secrets, though. It’ll be hard to keep them from the only other neighbor on his floor — Gawker guru Nick Denton.