Los Angeles Times May 21, 1991, Tuesday, Home Edition MORNING REPORT: POP/ROCK By ALEENE MacMINN , Arts and entertainment reports from The Times, national and international news services and the nation's press. Settling the Debt: Rap star M. C. Hammer is a man of his word, making good on his offer to pay for Sinead O'Connor's flight from Los Angeles to London. The Irish singer received a check for $2,624 from the rapper Monday without comment. Hammer had been irritated over her comments about "false and materialistic values in the record industry," and said he'd gladly pay the fare if she wanted to return home. O'Connor good-naturedly sent him a bill. Meanwhile, a spokeswoman for O'Connor says the singer will release a four-song "mini album" this summer and donate the royalties to Kurdish refugee relief efforts. The collection will include a new song, "Special Child," and a live version of her hit version of Prince's "Nothing Compares 2 U." ALEENE MacMINN