Fix index

Author: kgryte

lib/node_modules/@stdlib/assert/is-negative-number-array/benchmark/benchmark.js

@@ -49,7 +49,7 @@ function createBenchmark( fcn, len, primitives ) {
 		b.tic();
 		for ( i = 0; i < b.iterations; i++ ) {
 			// Note: we are testing the worst case scenario where a function must scan the entire array before finding a failing value.
-			x[ x.length ] = i * 3.14;
+			x[ len-1 ] = i * 3.14;
 			bool = fcn( x );
 			if ( !isBoolean( bool ) ) {
 				b.fail( 'should return a boolean' );