chore: update bench

Author: Neerajpathak07

lib/node_modules/@stdlib/stats/base/dists/gamma/entropy/benchmark/benchmark.js

@@ -34,6 +34,7 @@ var entropy = require( './../lib' );
 bench( pkg, function benchmark( b ) {
 	var alpha;
 	var beta;
+	var len;
 	var y;
 	var i;
 

lib/node_modules/@stdlib/stats/base/dists/gamma/entropy/benchmark/benchmark.native.js

@@ -43,6 +43,7 @@ var opts = {
 bench( pkg+'::native', opts, function benchmark( b ) {
 	var alpha;
 	var beta;
+	var len;
 	var y;
 	var i;