Only report that GPU commands are available when the queue is not empty. (#1656)

* Only report that commands are available when the queue is not empty.

* Address Feedback

Co-authored-by: FICTURE7 <FICTURE7@gmail.com>

Co-authored-by: FICTURE7 <FICTURE7@gmail.com>

Ryujinx.Graphics.Gpu/Engine/GPFifo/GPFifoDevice.cs

@@ -163,7 +163,7 @@ namespace Ryujinx.Graphics.Gpu.Engine.GPFifo
         /// <returns>True if commands were received, false if wait timed out</returns>
         public bool WaitForCommands()
         {
-            return _event.WaitOne(8);
+            return _event.WaitOne(8) && !_commandBufferQueue.IsEmpty;
         }
 
         /// <summary>