isl_convex_hull.c: modulo_affine_hull: fix potential memory leak on error path
isl_convex_hull.c: modulo_affine_hull: fix potential memory leak on error path

Signed-off-by: Sven Verdoolaege <235c10dd23b819f81cdc9756a251746bc184cab6@gmail.com>

Meinersbur/isl,Meinersbur/isl,inducer/isl-mirror,nicolasvasilache/isl,nicolasvasilache/isl,nicolasvasilache/isl,tobig/isl,tobig/isl,PollyLabs/isl,inducer/isl-mirror,PollyLabs/isl,nicolasvasilache/isl,PollyLabs/isl,inducer/isl-mirror,PollyLabs/isl,nicolasvasilache/isl,inducer/isl-mirror,tobig/isl,tobig/isl,Meinersbur/isl,PollyLabs/isl,Meinersbur/isl,inducer/isl-mirror