Fixed vector select codegen. Removed printfs.
Fixed vector select codegen. Removed printfs.

Former-commit-id: 32872cbd7357fdd4ad5fd52b91d44c93f2b74672
darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide