mm/memory_hotplug: make HWPoisoned dirty swapcache pages unmovable

mm/memory_hotplug: make HWPoisoned dirty swapcache pages unmovable

HWPoisoned dirty swapcache pages are kept for killing owner processes.  We
should not offline these pages or do_swap_page() would access the offline
pages and lead to bad ending.

Link: https://lkml.kernel.org/r/20210821094246.10149-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>