test: remove unused callback variables

Unused variables were removed from stream-exception test.

PR-URL: #47167
Reviewed-By: Yagiz Nizipli <[email protected]>
Reviewed-By: Debadree Chatterjee <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Daijiro Wachi <[email protected]>

test/parallel/test-wrap-js-stream-exceptions.js

@@ -11,7 +11,7 @@ process.once('uncaughtException', common.mustCall((err) => {
 
 const socket = new JSStreamWrap(new Duplex({
   read: common.mustCall(),
-  write: common.mustCall((buffer, data, cb) => {
+  write: common.mustCall(() => {
     throw new Error('exception!');
   })
 }));