remove duplicate declaration of isl_multi_aff_product
remove duplicate declaration of isl_multi_aff_product

This was missing from 187ec0e (generalize isl_multi_aff_product,
Fri Jun 28 12:57:46 2013 +0200).

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

BenzoSM/isl,BenzoSM/isl,nicolasvasilache/isl,inducer/isl-mirror,Distrotech/isl,Distrotech/isl,UBERTC/isl,PollyLabs/isl,inducer/isl-mirror,nicolasvasilache/isl,tobig/isl,inducer/isl-mirror,PollyLabs/isl,Meinersbur/isl,Distrotech/isl,UBERTC/isl,Meinersbur/isl,inducer/isl-mirror,PollyLabs/isl,UBERTC/isl,nicolasvasilache/isl,tobig/isl,BenzoSM/isl,tobig/isl,nicolasvasilache/isl,Distrotech/isl,UBERTC/isl,Meinersbur/isl,BenzoSM/isl,Meinersbur/isl,nicolasvasilache/isl,PollyLabs/isl,PollyLabs/isl,inducer/isl-mirror,BenzoSM/isl,Distrotech/isl,tobig/isl