SW RAID: Delete root device hint

The default root device hint can be retained and influence nodes
upon later test jobs. Since this is not a required piece of
configuration for non-raid jobs, we should go ahead and unset
the value.

Change-Id: I1199bd817438dfefdd96199dc52f438b184ad9df
diff --git a/ironic_tempest_plugin/tests/scenario/baremetal_standalone_manager.py b/ironic_tempest_plugin/tests/scenario/baremetal_standalone_manager.py
index 9948ca8..3605c28 100644
--- a/ironic_tempest_plugin/tests/scenario/baremetal_standalone_manager.py
+++ b/ironic_tempest_plugin/tests/scenario/baremetal_standalone_manager.py
@@ -602,6 +602,11 @@
         # So we only move the node to active (verifying deployment).
         self.set_node_to_active()
 
+    def remove_root_device_hint(self):
+        patch = [{'path': '/properties/root_device',
+                  'op': 'remove'}]
+        self.update_node(self.node['uuid'], patch=patch)
+
     def rescue_unrescue(self):
         rescue_password = uuidutils.generate_uuid()
         self.rescue_node(self.node['uuid'], rescue_password)
diff --git a/ironic_tempest_plugin/tests/scenario/ironic_standalone/test_cleaning.py b/ironic_tempest_plugin/tests/scenario/ironic_standalone/test_cleaning.py
index eb0d4d2..ef74e01 100644
--- a/ironic_tempest_plugin/tests/scenario/ironic_standalone/test_cleaning.py
+++ b/ironic_tempest_plugin/tests/scenario/ironic_standalone/test_cleaning.py
@@ -106,6 +106,10 @@
     @utils.services('image', 'network')
     def test_software_raid(self):
         self.build_raid_and_verify_node()
+        # NOTE(TheJulia): tearing down/terminating the instance does not
+        # remove the root device hint, so it is best for us to go ahead
+        # and remove it before exiting the test.
+        self.remove_root_device_hint()
 
 
 class SoftwareRaidDirect(bsm.BaremetalStandaloneScenarioTest):
@@ -138,3 +142,7 @@
     @utils.services('image', 'network')
     def test_software_raid(self):
         self.build_raid_and_verify_node()
+        # NOTE(TheJulia): tearing down/terminating the instance does not
+        # remove the root device hint, so it is best for us to go ahead
+        # and remove it before exiting the test.
+        self.remove_root_device_hint()