It wasn't his case . . . his girl . . . or his problem . . . but Johnny Liddell had a personal interest in this little caper.He didn't ask to be the Feds' ''receiver'' on a pass of inside info on the smuggling racket, but he was. He didn't ask to have a couple of hoods beat the living daylights out of him to get the info back, but they did. As a matter of fact, for the first time in his life, Johnny Liddell wasn't asking for trouble.But when a lovely doll invited him to see her later, and murder turned later into never again, Johnny asked in - in to the bloody end.