memory-failure: remove calls to page_mapping()

This is mostly just inlining page_mapping() into the two callers.

Link: https://lkml.kernel.org/r/20240423225552.4113447-4-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory-failure.c

@@ -216,6 +216,7 @@ EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
 
 static int hwpoison_filter_dev(struct page *p)
 {
+	struct folio *folio = page_folio(p);
 	struct address_space *mapping;
 	dev_t dev;
 
@@ -223,7 +224,7 @@ static int hwpoison_filter_dev(struct page *p)
 	    hwpoison_filter_dev_minor == ~0U)
 		return 0;
 
-	mapping = page_mapping(p);
+	mapping = folio_mapping(folio);
 	if (mapping == NULL || mapping->host == NULL)
 		return -EINVAL;
 
@@ -1090,7 +1091,8 @@ static int me_pagecache_clean(struct page_state *ps, struct page *p)
  */
 static int me_pagecache_dirty(struct page_state *ps, struct page *p)
 {
-	struct address_space *mapping = page_mapping(p);
+	struct folio *folio = page_folio(p);
+	struct address_space *mapping = folio_mapping(folio);
 
 	SetPageError(p);
 	/* TBD: print more information about the file. */