A retired mail carrier from Quincy has been accused of keeping his golf-playing and landscaping a secret while collecting worker’s compensation payments. Federal prosecutors said Daniel T. Driscoll, 50, was indicted in Boston federal court this week. Driscoll was accused of submitting false documents and forms to the U.S. Postal Service, his former employer, and to the Department of Labor, in which he failed to disclose his true ability to work and medical condition. Prosecutors said he didn’t report his frequent participation in physical activities from August through October of 2009.