message: rafs: fix root inode permission for lookup and readdir
  We need to set it for lookup and readdir as well so that it is
  consistent with getattr.
diff: @@ -483,6 +483,14 @@ impl Rafs {
  entry.attr.st_mtime = self.i_time as i64;
  }
  + // Only touch permissions bits. This trick is some sort of workaround
  + // since nydusify gives root directory permission of 0o750 and fuse mount
  + // options `rootmode=` does not affect root directory's permission bits, ending
  + // up with preventing other users from accessing the container rootfs.
  + if entry.inode == ROOT_ID {
  + entry.attr.st_mode = entry.attr.st_mode & !0o777 | 0o755;
  + }
  +
  entry
  }
  }
  