To say that critics have not been kind to Shane Salerno’s “Salinger” is an understatement. They call it subjective to the point of hagiography, bloated and overlong, the ultimate intrusion in the life of an author who lived on the equivalent of a mountaintop in order to be left alone by the myriad fans enthralled for the last two generations by his single book, “The Catcher in the Rye.” They say the music is syrupy