Remove unused function from median3x3
Remove unused function from median3x3

jiawen/Halide,ronen/Halide,psuriana/Halide,kgnk/Halide,kgnk/Halide,jiawen/Halide,ronen/Halide,psuriana/Halide,jiawen/Halide,ronen/Halide,ronen/Halide,kgnk/Halide,ronen/Halide,kgnk/Halide,kgnk/Halide,ronen/Halide,ronen/Halide,kgnk/Halide,psuriana/Halide,jiawen/Halide,jiawen/Halide,psuriana/Halide,jiawen/Halide,kgnk/Halide,psuriana/Halide,jiawen/Halide,kgnk/Halide,ronen/Halide,psuriana/Halide,psuriana/Halide