Subject: don't leave orhpaned swap cache after ksm merging

From: Andrea Arcangeli <aarcange@redhat.com>

When swapcache is replaced by a ksm page don't leave orhpaned swap cache.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---

diff --git a/mm/ksm.c b/mm/ksm.c
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -817,7 +817,7 @@ static int replace_page(struct vm_area_s
 	set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
 
 	page_remove_rmap(page);
-	put_page(page);
+	free_page_and_swap_cache(page);
 
 	pte_unmap_unlock(ptep, ptl);
 	err = 0;