test_migrations: Avoid returning a filter object for python3

Otherwise it confuses oslo.db.

Closes-Bug: #1522731
Change-Id: I1a246eea9adef10ec6c025e9b620f87ee9318dd7

diff --git a/neutron/tests/functional/db/test_migrations.py b/neutron/tests/functional/db/test_migrations.py
index b46f24931833b2146f4132823273bbd8e64972dc..bb2491e5e282060881bba214b688a74c7eec1ceb 100644 (file)
--- a/neutron/tests/functional/db/test_migrations.py
+++ b/neutron/tests/functional/db/test_migrations.py
@@ -131,7 +131,7 @@ class _TestModelsMigrations(test_migrations.ModelsMigrationsSync):
             object_, name, type_, reflected, compare_to)
 
     def filter_metadata_diff(self, diff):
-        return filter(self.remove_unrelated_errors, diff)
+        return list(filter(self.remove_unrelated_errors, diff))
 
     # Remove some difference that are not mistakes just specific of
     # dialects, etc