warpAffine: use mix
warpAffine: use mix

Former-commit-id: 6a04007e731a2f38d7720073e034403b170ecb64
rbaghdadi/pencil-benchmark,dividiti/pencil-benchmark,pencil-language/pencil-benchmark,dividiti/pencil-benchmark,rbaghdadi/pencil-benchmark,rbaghdadi/pencil-benchmark,pencil-language/pencil-benchmark,pencil-language/pencil-benchmark,dividiti/pencil-benchmark