Use page->lru.next to implement the singly linked list of pages rather than
the struct deferred_page which needs to be allocated and freed for each
page.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>