Fix failing policy_AUServer.AUDisabled*.

The test was running its cleanup() twice and so failed to ping the
already closed policy server on the second attempt.

BUG=chromium:1053656
TEST=policy_AUServer.AUDisabled on kevin

Change-Id: Ib5c4bb1068767d9fc0677923484fce70ddc6292c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2354764
Tested-by: David Haddock <dhaddock@chromium.org>
Reviewed-by: Kyle Shimabukuro <kyleshima@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: David Haddock <dhaddock@chromium.org>
(cherry picked from commit f7e040d10a9b202b059c21bc0d89fc557a8c986f)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2364521
Reviewed-by: David Haddock <dhaddock@chromium.org>
diff --git a/client/site_tests/policy_DeviceAutoUpdateDisabled/policy_DeviceAutoUpdateDisabled.py b/client/site_tests/policy_DeviceAutoUpdateDisabled/policy_DeviceAutoUpdateDisabled.py
index 308d43d..92a3b39 100644
--- a/client/site_tests/policy_DeviceAutoUpdateDisabled/policy_DeviceAutoUpdateDisabled.py
+++ b/client/site_tests/policy_DeviceAutoUpdateDisabled/policy_DeviceAutoUpdateDisabled.py
@@ -93,4 +93,3 @@
             self._test_update_disabled(nebraska.get_update_url(),
                                        should_update=case is not True)
 
-        self.cleanup()