OClCollMeshEngn: call clFlush+clFinish after setup()

This ensures that all operations enqueued during setup() get fully
executed before any requests come in.

stimBuffApis/livoxGen1/openClCollatingAndMeshingEngine.cpp

@@ -242,6 +242,8 @@ bool OpenClCollatingAndMeshingEngine::setup()
 		goto cleanup;
 	}
 
+	clFlush(commandQueue);
+	clFinish(commandQueue);
 	shouldAcceptRequests = true;
 	return true;