bench: refactor to use string interpolation in array/base/banded/filled2d-by

PR-URL: #8801
Ref: #8647
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: ksuraev

lib/node_modules/@stdlib/array/base/banded/filled2d-by/benchmark/benchmark.size.js

@@ -26,6 +26,7 @@ var floor = require( '@stdlib/math/base/special/floor' );
 var sqrt = require( '@stdlib/math/base/special/sqrt' );
 var isArrayArray = require( '@stdlib/assert/is-array-array' );
 var constantFunction = require( '@stdlib/utils/constant-function' );
+var format = require( '@stdlib/string/format' );
 var pkg = require( './../package.json' ).name;
 var filled2dBy = require( './../lib' );
 
@@ -97,7 +98,7 @@ function main() {
 		N = floor( sqrt( pow( 10, i ) ) );
 
 		f = createBenchmark( N, k, k );
-		bench( pkg+':ku='+k+',kl='+k+',size='+(N*N), f );
+		bench( format( '%s:ku=%d,kl=%d,size=%d', pkg, k, k, N*N ), f );
 	}
 }