test: removed default message from assert.strictEqual

Use the `assert.strictEqual()` default message instead of a static
message to include the actual and expected value.

PR-URL: #19660
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-net-server-pause-on-connect.js

@@ -34,7 +34,7 @@ const server1ConnHandler = (socket) => {
       assert.fail('data event should not have happened yet');
     }
 
-    assert.strictEqual(data.toString(), msg, 'invalid data received');
+    assert.strictEqual(data.toString(), msg);
     socket.end();
     server1.close();
   });
@@ -46,12 +46,11 @@ const server1 = net.createServer({ pauseOnConnect: true }, server1ConnHandler);
 
 const server2ConnHandler = (socket) => {
   socket.on('data', function(data) {
-    assert.strictEqual(data.toString(), msg, 'invalid data received');
+    assert.strictEqual(data.toString(), msg);
     socket.end();
     server2.close();
 
-    assert.strictEqual(server1Sock.bytesRead, 0,
-                       'no data should have been read yet');
+    assert.strictEqual(server1Sock.bytesRead, 0);
     server1Sock.resume();
     stopped = false;
   });