bench: fix missing namespace

Signed-off-by: Athan <[email protected]>

Author: kgryte

lib/node_modules/@stdlib/stats/strided/dztest2/benchmark/benchmark.ndarray.js

@@ -97,7 +97,7 @@ function main() {
 	for ( i = min; i <= max; i++ ) {
 		len = pow( 10, i );
 		f = createBenchmark( len );
-		bench( pkg+':len='+len, f );
+		bench( pkg+':ndarray:len='+len, f );
 	}
 }