sunrpc: clnt: Add missing braces

commit cac5d07e3ca696dcacfb123553cf6c722111cfd3 upstream.

Add a missing set of braces that commit 4e0038b6b24
("SUNRPC: Move clnt->cl_server into struct rpc_xprt")
forgot.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>