patch applied (ghc-6.6/nofib): Make primetest main be IO () so ghci doesn' t print the result

[Ian Lynagh]

Mon Dec 11 05:45:13 PST 2006  Ian Lynagh <igloo at earth.li>
  * Make primetest main be IO () so ghci doesn't print the result

    M ./spectral/primetest/Main.lhs -1 +2