patch applied (cabal): Remove handling for .hi-boot files, which was only needed for ghc-6.2

[Duncan Coutts]

Tue Jan 29 16:18:45 PST 2008  Duncan Coutts <duncan at haskell.org>
  * Remove handling for .hi-boot files, which was only needed for ghc-6.2
  which we have removed support for. It is not clear if we need any similar
  handling for .hs-boot files. These were also the only uses of smartCopySources
  which used exitIfNone set to False.

    M ./Distribution/Simple/GHC.hs -6 +2