[X86] Update AVX512-VNNI mask intrinsic tests to avoid adds

[X86] Update AVX512-VNNI mask intrinsic tests to avoid adds

As noticed in D119654, by adding the masked intrinsics results together we can end up with the selects being canonicalized away from the intrinsic - this isn't what we want to test here so replace with a insertvalue chain into a aggregate instead to retain all the results.