test: change callback function to arrow function

PR-URL: #24419
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ouyang Yadong <oyydoibh@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

test/parallel/test-zlib-invalid-input.js

@@ -43,7 +43,7 @@ const unzips = [
 
 nonStringInputs.forEach(common.mustCall((input) => {
   // zlib.gunzip should not throw an error when called with bad input.
-  zlib.gunzip(input, function(err, buffer) {
+  zlib.gunzip(input, (err, buffer) => {
     // zlib.gunzip should pass the error to the callback.
     assert.ok(err);
   });