stream: apply another minor perf improvement in stream/new

Author: jasnell

lib/internal/streams/new/broadcast.js

@@ -352,7 +352,6 @@ class BroadcastImpl {
           consumer.resolve = null;
           consumer.reject = null;
           resolve({ done: false, value: chunk });
-          this._tryTrimBuffer();
         }
       }
     }