mm/page_alloc.c: print reserved_highatomic info

mm/page_alloc.c: print reserved_highatomic info

Print nr_reserved_highatomic in show_free_areas, because when alloc_harder
is false, this value will be subtracted from the free_pages in
__zone_watermark_ok.  Printing this value can help analyze memory
allocaction failure issues.

Link: http://lkml.kernel.org/r/19515f3de2fb6abe66b52e03e4b676a21e82beda.1573634806.git.lijiazi@xiaomi.com
Signed-off-by: lijiazi <lijiazi@xiaomi.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>