Even before his piece of the action in the film version of his novel The Exorcist gave him $38 million in wherewithal, author William Peter Blatty was possessed by the idea of owning restaurants. His first venture was The Palm, in Los Angeles, where even Lotusland is boggled by such specialties as 20-pound lobsters. In January, Blatty and a Dallas pal and associate, manufacturers’ rep Jim Butler, will open Chops, at the former site of Calluaud on Fairmount Street. Blatty and the Irish-born Butler, who have pub-crawled together from Majorca to Hungary and dined at most of the Guide Mi-chelin’s three-star restaurants, say that Chops will be tony but not Continental, that there will be no cute theme, and that if comparisons must be made, the feel and cuisine will be “Savoy Grillish.”