patch applied (cabal): Fix non-fatal problem with ' setup haddock' for an exe package

[Simon Marlow]

Tue Jan  9 05:37:51 PST 2007  Simon Marlow <simonmar at microsoft.com>
  * Fix non-fatal problem with 'setup haddock' for an exe package
  For some unknown reason, we were passing --use-package=P to haddock,
  where P is the name of the current executable package.  This can never
  work, since P is not a library and will not be installed.  Fortunately
  Haddock ignores the error and continues anyway.
  

    M ./Distribution/Simple.hs -1 +1