Skip verifying empty devices in test_tagged_attachment until bug is fixed

We have a non-trivial amount of failures due to bug 1775947 [1]
and so far attempts at debugging the issue haven't proved
fruitful, so let's skip the last (problematic) portion of the
test until we can get a recreate with proper debug to help
isolate the problem.

Related nova debug patch: https://review.openstack.org/584032

[1] http://status.openstack.org/elastic-recheck/#1775947

Change-Id: I3104041cb66f912727aabd6c5894600dc87a1229
Related-Bug: #1775947

tempest/api/compute/servers/test_device_tagging.py

@@ -382,5 +382,8 @@ class TaggedAttachmentsTest(DeviceTaggingBase):
         waiters.wait_for_interface_detach(self.interfaces_client,
                                           server['id'],
                                           interface['port_id'])
-        self.verify_metadata_from_api(server, ssh_client,
-                                      self.verify_empty_devices)
+        # FIXME(mriedem): The assertion that the tagged devices are removed
+        # from the metadata for the server is being skipped until bug 1775947
+        # is fixed.
+        # self.verify_metadata_from_api(server, ssh_client,
+        #                               self.verify_empty_devices)