Apply suggestions from code review

Co-authored-by: Athan <kgryte@gmail.com>
Signed-off-by: Athan <kgryte@gmail.com>

Author: kgryte

lib/node_modules/@stdlib/blas/base/ndarray/gcopy/benchmark/benchmark.js

@@ -74,7 +74,7 @@ function createBenchmark( len ) {
 		for ( i = 0; i < b.iterations; i++ ) {
 			z = gcopy( [ x, y ] );
 			if ( typeof z !== 'object' ) {
-				b.fail( 'should not return NaN' );
+				b.fail( 'should return an ndarray' );
 			}
 		}
 		b.toc();