ocfs2: Call refcount tree remove process properly.

Now with xattr refcount support, we need to check whether
we have xattr refcounted before we remove the refcount tree.

Now the mechanism is:
1) Check whether i_clusters == 0, if no, exit.
2) check whether we have i_xattr_loc in dinode. if yes, exit.
2) Check whether we have inline xattr stored outside, if yes, exit.
4) Remove the tree.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h
index 7d6900c..1e3446a 100644
--- a/fs/ocfs2/refcounttree.h
+++ b/fs/ocfs2/refcounttree.h
@@ -90,4 +90,7 @@
 			    u32 cpos, u32 p_cluster, u32 num_clusters,
 			    struct ocfs2_cached_dealloc_ctxt *dealloc,
 			    struct ocfs2_post_refcount *post);
+int ocfs2_remove_refcount_tree(struct inode *inode, struct buffer_head *di_bh);
+int ocfs2_try_remove_refcount_tree(struct inode *inode,
+				   struct buffer_head *di_bh);
 #endif /* OCFS2_REFCOUNTTREE_H */