benchmark: swap var for let in buffer benchmarks

In benchmark buffers directory this changes for loops using var to let
when it applies for consistency

PR-URL: https://github.com/nodejs/node/pull/28867
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Khaidi Chu <i@2333.moe>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/benchmark/buffers/buffer-indexof-number.js b/benchmark/buffers/buffer-indexof-number.js
index bd3fe34f4d..b00a46524f 100644
--- a/benchmark/buffers/buffer-indexof-number.js
+++ b/benchmark/buffers/buffer-indexof-number.js
@@ -15,7 +15,7 @@ function main({ n, value }) {
 
   let count = 0;
   bench.start();
-  for (var i = 0; i < n; i++) {
+  for (let i = 0; i < n; i++) {
     count += aliceBuffer.indexOf(value, 0, undefined);
   }
   bench.end(n);