Fix issues with NEON code in pipeline and tests

lightmotif-bench/dna.rs

lightmotif/benches/score.rs

lightmotif/benches/stripe.rs

lightmotif/src/pli/mod.rs

lightmotif/src/pli/platform/neon.rs

lightmotif/src/scan.rs

lightmotif/tests/dna.rs