NFSD: Remove spurious cb_setup_err tracepoint

This path is not really an error path, so the tracepoint I added
there is just noise.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4callback.c

@@ -915,10 +915,8 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
 		args.authflavor = clp->cl_cred.cr_flavor;
 		clp->cl_cb_ident = conn->cb_ident;
 	} else {
-		if (!conn->cb_xprt) {
-			trace_nfsd_cb_setup_err(clp, -EINVAL);
+		if (!conn->cb_xprt)
 			return -EINVAL;
-		}
 		clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
 		clp->cl_cb_session = ses;
 		args.bc_xprt = conn->cb_xprt;