fixed imports

benches/multithreading.rs

@@ -4,7 +4,7 @@
 //! Each thread will calculate a partial dot product of two different vectors composed of 1,000,000 64-bit
 //! double precision floating point values.
 
-use std::{num::NonZeroUsize, sync::Arc};
+use std::{sync::Arc};
 
 use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion, Throughput};
 use imsearch::multithreading::ThreadPool;