patch applied (packages/mtl): use Control.Monad.Instances from base

[Ross Paterson]

Mon Apr 10 04:25:33 PDT 2006  Ross Paterson <ross at soi.city.ac.uk>
  * use Control.Monad.Instances from base

    M ./Control/Monad/Error.hs -4 +1
    M ./Control/Monad/Reader.hs -10 +1