migrate: convert migrate_pages() to use folios

[ Upstream commit eaec4e63 ]

Quite straightforward, the page functions are converted to corresponding
folio functions.  Same for comments.

THP specific code are converted to be large folio.

Link: https://lkml.kernel.org/r/20221109012348.93849-3-ying.huang@intel.com


Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 35e41024 ("vmscan,migrate: fix page count imbalance on node stats when demoting pages")
Signed-off-by: Sasha Levin <sashal@kernel.org>