File libdlm-gcc47.patch of Package libdlm

Index: libdlm/group/include/rbtree.h
===================================================================
--- libdlm.orig/group/include/rbtree.h
+++ libdlm/group/include/rbtree.h
@@ -91,6 +91,8 @@ static inline struct page * rb_insert_pa
 -----------------------------------------------------------------------
 */
 
+#include <stddef.h> // for NULL
+
 #ifndef	_LINUX_RBTREE_H
 #define	_LINUX_RBTREE_H