Fix unit test

Author: BryanMLima

plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtPrepareForMigrationCommandWrapperTest.java

@@ -30,12 +30,14 @@
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.Spy;
-import org.mockito.junit.MockitoJUnitRunner;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
 
 import java.util.HashMap;
 import java.util.Map;
 
-@RunWith(MockitoJUnitRunner.class)
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(value = {LibvirtPrepareForMigrationCommandWrapper.class})
 public class LibvirtPrepareForMigrationCommandWrapperTest {
 
     @Mock