Fixed some flake8 errors from recent commits.

django/contrib/admin/checks.py

@@ -96,8 +96,8 @@ class BaseModelAdminChecks(object):
             ]
 
         return list(chain(*[
-                self._check_field_spec(cls, model, field_name, 'fields')
-                for field_name in cls.fields
+            self._check_field_spec(cls, model, field_name, 'fields')
+            for field_name in cls.fields
         ]))
 
     def _check_fieldsets(self, cls, model):
@@ -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
 

django/views/debug.py

@@ -479,7 +479,7 @@ def technical_404_response(request, exception):
         error_url = exception.path
     except AttributeError:
         tried = []
-        error_url = request.path_info[1:] # Trim leading slash
+        error_url = request.path_info[1:]  # Trim leading slash
     else:
         if (not tried                           # empty URLconf
             or (request.path == '/'