mm: double mark_page_accessed() in read_cache_page_async()

Fix a post-2.6.21 regression.

read_cache_page_async() has two invocations of mark_page_accessed() which will
launch pages right onto the active list.

Remove the first one, keeping the latter one.  This avoids marking unwanted
pages active (in the retry loop).
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/filemap.c

@@ -1786,7 +1786,6 @@ struct page *read_cache_page_async(struct address_space *mapping,
 	page = __read_cache_page(mapping, index, filler, data);
 	if (IS_ERR(page))
 		return page;
-	mark_page_accessed(page);
 	if (PageUptodate(page))
 		goto out;