Fix resource name in test_crud_vm_firewall_rules

Test stats after this CL
========================
Ran 58 tests in 4490.629s

FAILED (SKIP=1, errors=7, failures=18)

test/test_security_service.py

@@ -97,7 +97,7 @@ class CloudSecurityServiceTestCase(ProviderTestBase):
 
     @helpers.skipIfNoService(['security.vm_firewalls'])
     def test_crud_vm_firewall_rules(self):
-        name = 'cb-crudfw_rules-{0}'.format(helpers.get_uuid())
+        name = 'cb-crudfw-rules-{0}'.format(helpers.get_uuid())
 
         # Declare these variables and late binding will allow
         # the cleanup method access to the most current values