test: swap actual&optional params

PR-URL: #24426
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>

test/pummel/test-stream-pipe-multi.js

@@ -66,8 +66,8 @@ FakeStream.prototype.close = function() {
 
 // expect all streams to close properly.
 process.on('exit', function() {
-  assert.strictEqual(cnt, wclosed);
-  assert.strictEqual(cnt, rclosed);
+  assert.strictEqual(wclosed, cnt);
+  assert.strictEqual(rclosed, cnt);
 });
 
 for (let i = 0; i < chunkSize; i++) {