erofs-utils: fsck: convert to use erofs_iterate_dir()

No need to open code after erofs_iterate_dir() is finalized in
liberofs.

However, there are still some TODOs for fsck:
 - Avoid too deep recursive traversal, sceptically forming a loop;
 - Check link counts at runtime to keep consistency;
 - Check if any ftype / i_mode mismatches.

Link: https://lore.kernel.org/r/20211216012436.10111-2-xiang@kernel.org
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
1 file changed