llvmGen: Fix minor correctness issue
llvmGen: Fix minor correctness issue

The alias is of type i8, so its global variable name
should have type i8*. Anyway we should never deal
with pointers to (i8*)!

sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc