fs: btrfs: Imeplement btrfs_list_subvols() using new infrastructure

Reimplement btrfs_list_subvols() to use new code.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek BehĂșn <marek.behun@nic.cz>
1 file changed