small changes to scan op

theano/sandbox/scan.py

@@ -406,7 +406,7 @@ class Scan(theano.Op):
             warning('Can not compute gradients if inplace or updates ' \
                     'are used. Use force_gradient if you know for sure '\
                     'that the gradient can be computed automatically.')
-            return [None for i in inputs]
+            return [None for i in args]
         else:
             # forward pass 
             y = self(*args)