tempest: Fix qos extension check

Fix issues introduced by the recent change. [1]

[1] I88e59cdbd79afb5337052ba3e5aecb96c7c8ea1c

Closes-Bug: #1649171
Change-Id: I2a2b627fd30ec564d8c8566fd3e46eb889e15dc9
diff --git a/neutron/tests/tempest/scenario/test_qos.py b/neutron/tests/tempest/scenario/test_qos.py
index f44e631..b558438 100644
--- a/neutron/tests/tempest/scenario/test_qos.py
+++ b/neutron/tests/tempest/scenario/test_qos.py
@@ -80,8 +80,8 @@
     FILE_PATH = "/tmp/img"
 
     @classmethod
-    @base_api.require_qos_rule_type(qos_consts.RULE_TYPE_BANDWIDTH_LIMIT)
     @test.requires_ext(extension="qos", service="network")
+    @base_api.require_qos_rule_type(qos_consts.RULE_TYPE_BANDWIDTH_LIMIT)
     def resource_setup(cls):
         super(QoSTest, cls).resource_setup()