squash mm: Export migrate_page_... : also make it non-static

commit ce16887b69e94a8c0305e88c918989f8bc1bd6b7 upstream.
Signed-off-by: Willy Tarreau <w@1wt.eu>

mm/migrate.c

@@ -308,7 +308,7 @@ static inline bool buffer_migrate_lock_buffers(struct buffer_head *head,
  * 2 for pages with a mapping
  * 3 for pages with a mapping and PagePrivate/PagePrivate2 set.
  */
-static int migrate_page_move_mapping(struct address_space *mapping,
+int migrate_page_move_mapping(struct address_space *mapping,
 		struct page *newpage, struct page *page,
 		struct buffer_head *head, enum migrate_mode mode)
 {