chore: remove variable declaration

Signed-off-by: Philipp Burckhardt <[email protected]>

Author: Planeshifter

lib/node_modules/@stdlib/stats/base/dists/planck/mean/benchmark/benchmark.js

@@ -31,7 +31,6 @@ var mean = require( './../lib' );
 
 bench( pkg, function benchmark( b ) {
 	var lambda;
-	var len;
 	var y;
 	var i;