fsck.f2fs: fix to detect double '.' or '..'

If there are double '.' or '..' dirents in directory, fsck.f2fs won't
detect and repaire the issue correctly, fix it.

Reviewed-by: Sheng Yong <shengyong@oppo.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
3 files changed