host_no_sdn_controller: use pytest.fail() instead of pytest.skip()

Signed-off-by: Sebastien Marie <semarie@kapouay.eu.org>

Author: semarie

tests/network/conftest.py

@@ -6,4 +6,4 @@
 def host_no_sdn_controller(host: Host) -> None:
     """ An XCP-ng with no SDN controller. """
     if host.xe('sdn-controller-list', minimal=True):
-        pytest.skip("This test requires an XCP-ng with no SDN controller")
+        pytest.fail("This test requires an XCP-ng with no SDN controller")