BACKPORT: mm: page_alloc: batch vmstat updates in expand()

expand() currently updates vmstat for every subpage.  This is unnecessary,
since they're all of the same zone and migratetype.

Count added pages locally, then do a single vmstat update.

Link: https://lkml.kernel.org/r/20240327190111.GC7597@cmpxchg.org


Change-Id: I3373bb60d30f9a631a246d33e275a73229696726
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 883dd161)
[ Fix trivial conflict in expand() - Kalesh Singh]
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>