ntfs_get_nr_significant_bytes
rls += 1 + ntfs_get_nr_significant_bytes(rl->length - delta);
rls += ntfs_get_nr_significant_bytes(prev_lcn);
rls += 1 + ntfs_get_nr_significant_bytes(rl->length);
rls += ntfs_get_nr_significant_bytes(rl->lcn -
extern int ntfs_get_nr_significant_bytes(const s64 n);