Fixed some flake8 errors from recent commits.

django/contrib/admin/checks.py

@@ -145,8 +145,8 @@ class BaseModelAdminChecks(object):
                 )
             ]
         return list(chain(*[
-            self._check_field_spec(cls, model, fields, '%s[1][\'fields\']' % label)
-            for fields in fieldset[1]['fields']
+            self._check_field_spec(cls, model, fieldset_fields, '%s[1][\'fields\']' % label)
+            for fieldset_fields in fieldset[1]['fields']
         ]))
 
     def _check_field_spec(self, cls, model, fields, label):

django/core/urlresolvers.py

@@ -75,6 +75,7 @@ class Resolver404(Http404):
         self.path = path
         self.tried = tried
 
+
 class NoReverseMatch(Exception):
     pass