mm: return the folio from __read_swap_cache_async()

Patch series "More swap folio conversions".

These all seem like fairly straightforward conversions to me.  A lot of
compound_head() calls get removed.  And page_swap_info(), which is nice.


This patch (of 13):

Move the folio->page conversion into the callers that actually want that. 
Most of the callers are happier with the folio anyway.  If the
page_allocated boolean is set, the folio allocated is of order-0, so it is
safe to pass the page directly to swap_readpage().

Link: https://lkml.kernel.org/r/20231213215842.671461-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20231213215842.671461-2-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>