swap_cache_info are not statistics that could be easily used to tune
system performance because they are not easily accessile.  Also they can't
provide really useful info when OOM occurs.  Remove these statistics can
also help mitigate unneeded global swap_cache_info cacheline contention.

Link: https://lkml.kernel.org/r/20220608144031.829-4-linmiaohe@huawei.comSigned-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Suggested-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NMuchun Song <songmuchun@bytedance.com>
Acked-by: N"Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>