NFS implement v4.0 callback_ident

Use the small id to pointer translator service to provide a unique callback
identifier per SETCLIENTID call used to identify the v4.0 callback service
associated with the clientid.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e67e31c..c7782b2 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1612,6 +1612,7 @@
 #ifdef CONFIG_PROC_FS
 	rpc_proc_unregister("nfs");
 #endif
+	nfs_cleanup_cb_ident_idr();
 	unregister_nfs_fs();
 	nfs_fs_proc_exit();
 	nfsiod_stop();