movie ruined the book

[Mullins, Bill CIV (US)]

Fan/Critic to Famous Author:  "The movie ruined your book!"
 
Famous Author:  "No it didn't, the book is fine, right there on the shelf."
 
 
I associated this quote with Stephen King, probably from the intro to one of his novels.  But a little Googling shows that Allen Ginsberg and Larry Niven have said more or less the same thing, and that James M. Cain may have said it first. 
 
Does anyone know the original?  Is is Cain?

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