Correctly print --limit value passed via API

Passing an invalid limit value, for example '--limit -1'
in neutronclient, generates this error from the API:

  Bad limit request: Limit must be an integer 0 or
  greater and not '%d'.

It should print what was passed.

Closes-bug: #1649665

(cherry picked from commit e45d2a904d)

Change-Id: I9b8bd67d344cd91e008f7c897f1ea6a020a9c30b

neutron/api/api_common.py

@@ -121,13 +121,14 @@ def _get_pagination_max_limit():
 
 def _get_limit_param(request):
     """Extract integer limit from request or fail."""
+    limit = request.GET.get('limit', 0)
     try:
-        limit = int(request.GET.get('limit', 0))
+        limit = int(limit)
         if limit >= 0:
             return limit
     except ValueError:
         pass
-    msg = _("Limit must be an integer 0 or greater and not '%d'")
+    msg = _("Limit must be an integer 0 or greater and not '%s'") % limit
     raise exceptions.BadRequest(resource='limit', msg=msg)
 
 

neutron/tests/unit/api/v2/test_base.py

@@ -345,6 +345,7 @@ class APIv2TestCase(APIv2TestBase):
         res = self.api.get(_get_path('networks'),
                            {'limit': 'abc'}, expect_errors=True)
         self.assertEqual(exc.HTTPBadRequest.code, res.status_int)
+        self.assertIn('abc', res)
 
     def test_limit_with_infinite_pagination_max_limit(self):
         instance = self.plugin.return_value