A film on reclusive J.D. Salinger has created its own mystery in Hollywood. Harvey Weinstein bought “Salinger,” by director Shane Salerno about the enigmatic author, the same day as this year’s Academy Awards. But only a few execs at the Weinstein Co. have even seen the film, which comes out Sept. 6. It hasn’t been screened by press either because, sources said, Salerno doesn’t want any of its revelations to leak out. Advanced screenings are being set up, but viewers will have to sign nondisclosure agreements and bodyguards will accompany prints of the film. The director put $2 million of his own into the movie that took nine years to make. Salinger died in 2010, but his last work was published in 1965, and there have been rumors of unseen manuscripts.