BOSTON — Comedian Jay Leno will return to his alma mater Emerson College to deliver the commencement address this spring.The small liberal arts college located in Boston announced Tuesday that the 1973 grad will be speaking at the 134th commencement ceremony on May 11. Scott Simon, who hosts NPR's Weekend Edition Saturday, will be addressing the graduate students.Leno hosted NBC's late-night talk show "The Tonight Show" for more than two decades retiring in February.