SUNRPC: constify the rpc_program

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index f5188e1..144419a 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1274,11 +1274,11 @@
 extern const struct nfs_rpc_ops	nfs_v2_clientops;
 extern const struct nfs_rpc_ops	nfs_v3_clientops;
 extern const struct nfs_rpc_ops	nfs_v4_clientops;
-extern struct rpc_version	nfs_version2;
-extern struct rpc_version	nfs_version3;
-extern struct rpc_version	nfs_version4;
+extern const struct rpc_version nfs_version2;
+extern const struct rpc_version nfs_version3;
+extern const struct rpc_version nfs_version4;
 
-extern struct rpc_version	nfsacl_version3;
-extern struct rpc_program	nfsacl_program;
+extern const struct rpc_version nfsacl_version3;
+extern const struct rpc_program nfsacl_program;
 
 #endif