benchmark: remove duplicate ffi string length direct

Signed-off-by: HoonDongKang <d159123@naver.com>
PR-URL: https://github.com/nodejs/node/pull/66278
Reviewed-By: Daeyeon Jeong <daeyeon.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

benchmark/ffi/string-length-string-direct.js

@@ -1,28 +0,0 @@
-'use strict';
-
-const common = require('../common.js');
-const ffi = require('node:ffi');
-const { libraryPath, ensureFixtureLibrary } = require('./common.js');
-
-const bench = common.createBenchmark(main, {
-  n: [1e7],
-});
-
-ensureFixtureLibrary();
-
-const { lib, functions } = ffi.dlopen(libraryPath, {
-  string_length: { return: 'u64', arguments: ['pointer'] },
-});
-
-const fn = functions.string_length;
-const string = Buffer.from('hello\0');
-const pointer = ffi.getRawPointer(string);
-
-function main({ n }) {
-  bench.start();
-  for (let i = 0; i < n; ++i)
-    fn(pointer);
-  bench.end(n);
-
-  lib.close();
-}