mm/vmscan: use folio_migratetype() instead of get_pageblock_migratetype()

In skip_cma(), we can use folio_migratetype() to replace
get_pageblock_migratetype().

Link: https://lkml.kernel.org/r/20230825075735.52436-1-user@VERNHAO-MC1


Signed-off-by: Vern Hao <vernhao@tencent.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>