fs: Remove read_actor_t

This typedef is not used any more.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/fs.h

@@ -357,9 +357,6 @@ typedef struct {
 	int error;
 } read_descriptor_t;
 
-typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
-		unsigned long, unsigned long);
-
 struct address_space_operations {
 	int (*writepage)(struct page *page, struct writeback_control *wbc);
 	int (*readpage)(struct file *, struct page *);