DAMON's physical address space monitoring operations set is using folio
now.  Rename 'damon_pa_access_chk_result->page_sz' to reflect the fact.

Link: https://lkml.kernel.org/r/20230109213335.62525-5-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>