Fix XMLTestRunner

Author: zsxwing

python/pyspark/streaming/tests.py

@@ -1327,8 +1327,7 @@ def search_kinesis_asl_assembly_jar():
         sys.stderr.write("[Running %s]\n" % (testcase))
         tests = unittest.TestLoader().loadTestsFromTestCase(testcase)
         if xmlrunner:
-            result = unittest.main(tests, verbosity=3,
-                                   testRunner=xmlrunner.XMLTestRunner(output='target/test-reports'))
+            result = xmlrunner.XMLTestRunner(output='target/test-reports', verbosity=3).run(tests)
             if not result.wasSuccessful():
                 failed = True
         else: