ntfs_rl_are_mergeable
right = ntfs_rl_are_mergeable(src + ssize - 1, dst + loc + 1);
left = ntfs_rl_are_mergeable(dst + loc - 1, src);
right = ntfs_rl_are_mergeable(src + ssize - 1, dst + loc + 1);
left = ntfs_rl_are_mergeable(dst + loc - 1, src);