Fixed Unittest with an mock

jenkins/windows_c.cmd

@@ -1,5 +1,6 @@
 @REM Copyright (c) Microsoft. All rights reserved.
 @REM Licensed under the MIT license. See LICENSE file in the project root for full license information.
+@echo off
 
 setlocal
 

tests/mqtt_client_ut/mqtt_client_ut.c

@@ -1965,10 +1965,13 @@ TEST_FUNCTION(mqtt_client_dowork_does_nothing_if_disconnected_2)
     (void)mqtt_client_connect(mqttHandle, TEST_IO_HANDLE, &mqttOptions);
     umock_c_reset_all_calls();
 
+    STRICT_EXPECTED_CALL(xio_dowork(IGNORED_PTR_ARG));
+
     // act
     int result = mqtt_client_disconnect(mqttHandle, NULL, NULL);
     mqtt_client_dowork(mqttHandle);
 
+    ASSERT_ARE_EQUAL(int, 0, result);
     ASSERT_ARE_EQUAL(char_ptr, umock_c_get_expected_calls(), umock_c_get_actual_calls());
 
     // cleanup