filemap: remove PageHWPoison check from next_uptodate_page()

Pages are individually marked as suffering from hardware poisoning.
Checking that the head page is not hardware poisoned doesn't make
sense; we might be after a subpage.  We check each page individually
before we use it, so this was an optimisation gone wrong.  It will
cause us to fall back to the slow path when there was no need to do
that

Link: https://lkml.kernel.org/r/20211120174429.2596303-1-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NNaoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/filemap.c

@@ -3253,8 +3253,6 @@ static struct page *next_uptodate_page(struct page *page,
 			goto skip;
 		if (!PageUptodate(page) || PageReadahead(page))
 			goto skip;
-		if (PageHWPoison(page))
-			goto skip;
 		if (!trylock_page(page))
 			goto skip;
 		if (page->mapping != mapping)