erofs-utils: lib: set OVL_XATTR_ORIGIN for directories with whiteouts

erofs-utils: lib: set OVL_XATTR_ORIGIN for directories with whiteouts

Whiteouts are exposed in the overlayfs mount if these are from some
non-merged directory without OVL_XATTR_ORIGIN set on the directory.

To fix this, tag OVL_XATTR_ORIGIN (with empty value) on the parent
directory of whiteouts.

Fixes: 95d315fd7958 ("erofs-utils: introduce tarerofs")
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230909163240.42057-5-hsiangkao@linux.alibaba.com