There's only one caller.
Signed-off-by: David Sterba <dsterba@suse.com>
 
 int extent_writepages(struct extent_io_tree *tree,
                      struct address_space *mapping,
-                     get_extent_t *get_extent,
                      struct writeback_control *wbc)
 {
        int ret = 0;
        struct extent_page_data epd = {
                .bio = NULL,
                .tree = tree,
-               .get_extent = get_extent,
+               .get_extent = btrfs_get_extent,
                .extent_locked = 0,
                .sync_io = wbc->sync_mode == WB_SYNC_ALL,
        };
 
                              int mode);
 int extent_writepages(struct extent_io_tree *tree,
                      struct address_space *mapping,
-                     get_extent_t *get_extent,
                      struct writeback_control *wbc);
 int btree_write_cache_pages(struct address_space *mapping,
                            struct writeback_control *wbc);
 
        struct extent_io_tree *tree;
 
        tree = &BTRFS_I(mapping->host)->io_tree;
-       return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
+       return extent_writepages(tree, mapping, wbc);
 }
 
 static int