ocfs2: Add ocfs2_read_refcount_block.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile
index 0159607..31f25ce 100644
--- a/fs/ocfs2/Makefile
+++ b/fs/ocfs2/Makefile
@@ -28,6 +28,7 @@
 	locks.o			\
 	mmap.o 			\
 	namei.o 		\
+	refcounttree.o		\
 	resize.o		\
 	slot_map.o 		\
 	suballoc.o 		\