mm: huge_memory: use more folio api in __split_huge_page_tail()

Use more folio APIs to save six compound_head() calls in
__split_huge_page_tail().

Link: https://lkml.kernel.org/r/20231110033324.2455523-5-wangkefeng.wang@huawei.com


Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>