mm/page_alloc: remove the incorrect and misleading comment

The comment removed in this patch originally belonged to the
build_zonelists_in_zone_order() function, which was introduced by commit
f0c0b2b ("change zonelist order: zonelist order selection logic").

Later, commit c9bff3e ("mm, page_alloc: rip out ZONELIST_ORDER_ZONE")
removed build_zonelists_in_zone_order() but left its comment behind.

Subsequently, commit 9d3be21 ("mm, page_alloc: simplify zonelist
initialization") moved the node_order variable into build_zonelists(),
making the comment originally belonged to build_zonelists_in_zone_order()
appear as if it were part of build_zonelists().

Remove this misleading comment.

Link: https://lkml.kernel.org/r/20250115041634.63387-1-yuntao.wang@linux.dev
Signed-off-by: Yuntao Wang <yuntao.wang@linux.dev>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: ytcoode

mm/page_alloc.c

@@ -5159,13 +5159,6 @@ static void build_thisnode_zonelists(pg_data_t *pgdat)
 	zonerefs->zone_idx = 0;
 }
 
-/*
- * Build zonelists ordered by zone and nodes within zones.
- * This results in conserving DMA zone[s] until all Normal memory is
- * exhausted, but results in overflowing to remote node while memory
- * may still exist in local DMA zone.
- */
-
 static void build_zonelists(pg_data_t *pgdat)
 {
 	static int node_order[MAX_NUMNODES];