qapi: Drop conditionals for Python 2

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200304155932.20452-3-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
diff --git a/tests/qapi-schema/test-qapi.py b/tests/qapi-schema/test-qapi.py
index 41232c1..bee18ee 100755
--- a/tests/qapi-schema/test-qapi.py
+++ b/tests/qapi-schema/test-qapi.py
@@ -16,15 +16,11 @@
 import difflib
 import os
 import sys
+from io import StringIO
 
 from qapi.error import QAPIError
 from qapi.schema import QAPISchema, QAPISchemaVisitor
 
-if sys.version_info[0] < 3:
-    from cStringIO import StringIO
-else:
-    from io import StringIO
-
 
 class QAPISchemaTestVisitor(QAPISchemaVisitor):