JULY 22--While most celebrities are content to have news of the demise of their marriage surface via a divorce petition, James Brown decided not to wait until the onset of litigation against his wife Tomi. So the singing legend took out a full-page ad in this week's "Variety" to announce that the couple had made a "mutual show business decision" to "go their separate ways." Turns out their union was torpedoed by a "heavy demanding tour schedule." The ad's sad news, though, was lightened a bit by an accompanying photo of the Brown gang at Disney World. That's Goofy at left. (1 page)