[XFS] Fixed the inconsistency between attribute b-tree intermidiate node

and leaf blocks. The problem cam from xfsqa test 117.

SGI-PV: 940655
SGI-Modid: xfs-linux:xfs-kern:201527a

Signed-off-by: Yingping Lu <yingping@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>