Fix function signature
Fix function signature

Current signature is int*, but it actually returns a char* which gives a
warning. It still works because Perl declares the nativecall as a Str
anyway.  This just avoids the warning.

salortiz/rakudo,tbrowder/rakudo,labster/rakudo,nbrown/rakudo,MasterDuke17/rakudo,Gnouc/rakudo,tony-o/rakudo,nbrown/rakudo,lucasbuchala/rakudo,lucasbuchala/rakudo,labster/rakudo,Gnouc/rakudo,softmoth/rakudo,rakudo/rakudo,tony-o/rakudo,softmoth/rakudo,rakudo/rakudo,rakudo/rakudo,nbrown/rakudo,tony-o/rakudo,tbrowder/rakudo,lucasbuchala/rakudo,salortiz/rakudo,lucasbuchala/rakudo,softmoth/rakudo,tbrowder/rakudo,lucasbuchala/rakudo,tbrowder/rakudo,rakudo/rakudo,nbrown/rakudo,labster/rakudo,Gnouc/rakudo,tony-o/rakudo,softmoth/rakudo,salortiz/rakudo,MasterDuke17/rakudo,labster/rakudo,Gnouc/rakudo,tony-o/rakudo,MasterDuke17/rakudo,nbrown/rakudo,salortiz/rakudo,rakudo/rakudo,labster/rakudo,salortiz/rakudo,MasterDuke17/rakudo,MasterDuke17/rakudo,MasterDuke17/rakudo,salortiz/rakudo,Gnouc/rakudo,tbrowder/rakudo,labster/rakudo,rakudo/rakudo,softmoth/rakudo,Gnouc/rakudo,tony-o/rakudo,tbrowder/rakudo,nbrown/rakudo