mm: convert isolate_page() to mf_isolate_folio()

The only caller now has a folio, so pass it in and operate on it.  Saves
many page->folio conversions and introduces only one folio->page
conversion when calling isolate_movable_page().

Link: https://lkml.kernel.org/r/20231108182809.602073-6-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>