integration-cli: TestUserDefinedNetworkConnectDisconnectAlias return on failure

Have the test return immediately if the test does not pass instead of
stuck in `top`.

Signed-off-by: Andrew Hsu <andrewhsu@docker.com>

integration-cli/docker_cli_network_unix_test.go

@@ -1537,7 +1537,7 @@ func (s *DockerSuite) TestUserDefinedNetworkConnectDisconnectAlias(c *testing.T)
 	assert.NilError(c, err)
 
 	// verify the alias option is rejected when running on predefined network
-	out, _, err := dockerCmdWithError("run", "--rm", "--name=any", "--net-alias=any", "busybox:glibc", "top")
+	out, _, err := dockerCmdWithError("run", "--rm", "--name=any", "--net-alias=any", "busybox:glibc", "true")
 	assert.Assert(c, err != nil, "out: %s", out)
 	assert.Assert(c, strings.Contains(out, runconfig.ErrUnsupportedNetworkAndAlias.Error()))
 	// verify the alias option is rejected when connecting to predefined network