It seems to exist since the old times and never used once.  Remove them.

Link: https://lkml.kernel.org/r/20220525195220.10241-1-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>