set_page_refcounted() VM_BUG_ON fix

The current PageTail semantic is that a PageTail page is first a
PageCompound page.  So remove the redundant PageCompound test in
set_page_refcounted().

Signed-off-by: Qi Yong <qiyong@fc-cn.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/internal.h b/mm/internal.h
index 1e34d24..5a9a620 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -24,7 +24,7 @@
  */
 static inline void set_page_refcounted(struct page *page)
 {
-	VM_BUG_ON(PageCompound(page) && PageTail(page));
+	VM_BUG_ON(PageTail(page));
 	VM_BUG_ON(atomic_read(&page->_count));
 	set_page_count(page, 1);
 }