bench: minor string interpolation change in stats/incr/wmean

PR-URL: #9977

Reviewed-by: Philipp Burckhardt <pburckhardt@outlook.com>

Author: Om-A-osc

lib/node_modules/@stdlib/stats/incr/wmean/benchmark/benchmark.js

@@ -22,6 +22,7 @@
 
 var bench = require( '@stdlib/bench' );
 var randu = require( '@stdlib/random/base/randu' );
+var format = require( '@stdlib/string/format' );
 var pkg = require( './../package.json' ).name;
 var incrwmean = require( './../lib' );
 
@@ -46,7 +47,7 @@ bench( pkg, function benchmark( b ) {
 	b.end();
 });
 
-bench( pkg+'::accumulator', function benchmark( b ) {
+bench( format( '%s::accumulator', pkg ), function benchmark( b ) {
 	var acc;
 	var v;
 	var i;