We are moving extent_io_tree into it's on file, so separate out the
extent_state init stuff from extent_io_tree_init().
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>