mm: add nr_free_highatomic in show_free_areas

mm: add nr_free_highatomic in show_free_areas

commit c928807f6f6b6("mm/page_alloc: keep track of free highatomic")
adds a new variable nr_free_highatomic, which is useful for analyzing low
mem issues. add nr_free_highatomic in show_free_areas.

Signed-off-by: gao xu <gaoxu2@honor.com>
Link: https://lkml.kernel.org/r/d92eeff74f7a4578a14ac777cfe3603a@honor.com
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>