Patch from Nicolas Pitre

Before previous patch this driver compiled OK but was buggy.
Now it doesn't compile anymore as the bogus macro has been
deleted.  Fix that in any case.

The same fix has been committed to the MTD CVS already, but please forward 
this to Linus otherwise Lubbock won't compile from kernel.org tree anymore
(waiting for dwmw2 to update this might prove ... hrm ... long)