streams: Update test/parallel/test-duplex-error.js

Author: aelhor

test/parallel/test-duplex-error.js

@@ -6,15 +6,15 @@ const { duplexPair } = require('stream');
 
 const [sideA, sideB] = duplexPair();
 
-// Use common.mustCall inside the listeners to ensure they trigger
 sideA.on('error', common.mustCall((err) => {
+  assert.strictEqual(err.message, 'Simulated error');
 }));
 
 sideB.on('error', common.mustCall((err) => {
+  assert.strictEqual(err.message, 'Simulated error');
 }));
 
 sideA.resume();
 sideB.resume();
 
 sideB.destroy(new Error('Simulated error'));
-