bench: refactor to use string interpolation in buffer/ctor

PR-URL: #9552
Ref: #8647
Reviewed-by: Athan Reines <kgryte@gmail.com>
Co-authored-by: stdlib-bot <noreply@stdlib.io>

Author: whizzel

lib/node_modules/@stdlib/buffer/ctor/benchmark/benchmark.length.js

@@ -24,6 +24,7 @@ var bench = require( '@stdlib/bench' );
 var pow = require( '@stdlib/math/base/special/pow' );
 var isBuffer = require( '@stdlib/assert/is-buffer' );
 var isFunction = require( '@stdlib/assert/is-function' );
+var format = require( '@stdlib/string/format' );
 var pkg = require( './../package.json' ).name;
 var ctor = require( './../lib' );
 
@@ -98,7 +99,7 @@ function main() {
 	for ( i = min; i <= max; i++ ) {
 		len = pow( 10, i );
 		f = createBenchmark( len );
-		bench( pkg+':len='+len, f );
+		bench( format( '%s:len=%d', pkg, len ), f );
 	}
 }