llist: Add llist_next()

So we don't have to expose the struct list_node member.

Cc: Huang Ying <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1315836348.26517.41.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/llist.h b/include/linux/llist.h
index 27bbdf5..e2e96d0 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -138,6 +138,11 @@
 	return ACCESS_ONCE(head->first) == NULL;
 }
 
+static inline struct llist_node *llist_next(struct llist_node *node)
+{
+	return node->next;
+}
+
 /**
  * llist_add - add a new entry
  * @new:	new entry to be added