network: Fix subnet_allocation extension check.

This code checked for a "subnetpools" extension.  While it's commonly
referred to that way, and may have originally been called that, the
API extension is actually "subnet_allocation".  Nobody has probably
noticed this error as the default neutron jobs run with the
api_extensions configuration set to "all", so all checks like this
would return True.

Change-Id: I646b5e988bc6a9053d5361d81ed4c166fc670c7a
Signed-off-by: Russell Bryant <rbryant@redhat.com>
diff --git a/tempest/api/network/test_subnetpools_extensions.py b/tempest/api/network/test_subnetpools_extensions.py
index d027132..c6cc8e2 100644
--- a/tempest/api/network/test_subnetpools_extensions.py
+++ b/tempest/api/network/test_subnetpools_extensions.py
@@ -30,7 +30,7 @@
         Lists subnet pool.
         Show subnet pool details.
 
-    v2.0 of the Neutron API is assumed. It is assumed that subnetpools
+    v2.0 of the Neutron API is assumed. It is assumed that subnet_allocation
     options mentioned in the [network-feature-enabled] section and
     default_network option mentioned in the [network] section of
     etc/tempest.conf:
@@ -40,8 +40,8 @@
     @classmethod
     def skip_checks(cls):
         super(SubnetPoolsTestJSON, cls).skip_checks()
-        if not test.is_extension_enabled('subnetpools', 'network'):
-            msg = "subnet pools extension not enabled."
+        if not test.is_extension_enabled('subnet_allocation', 'network'):
+            msg = "subnet_allocation extension not enabled."
             raise cls.skipException(msg)
 
     @test.attr(type='smoke')