mm: page_alloc: remove unused parameter from reserve_highatomic_pageblock()

mm: page_alloc: remove unused parameter from reserve_highatomic_pageblock()

Just remove the redundant parameter alloc_order from
reserve_highatomic_pageblock(). No functional modification involved.

Link: https://lkml.kernel.org/r/20230809073323.1065286-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>