test: refactor test-fs-read-zero-length.js

PR-URL: https://github.com/nodejs/node/pull/10729
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

test/parallel/test-fs-read-zero-length.js

@@ -9,7 +9,7 @@ const fd = fs.openSync(filepath, 'r');
 const bufferAsync = Buffer.alloc(0);
 const bufferSync = Buffer.alloc(0);
 
-fs.read(fd, bufferAsync, 0, 0, 0, common.mustCall(function(err, bytesRead) {
+fs.read(fd, bufferAsync, 0, 0, 0, common.mustCall((err, bytesRead) => {
   assert.strictEqual(bytesRead, 0);
   assert.deepStrictEqual(bufferAsync, Buffer.alloc(0));
 }));