修复打印时间bug

src/main.cpp

@@ -18,6 +18,7 @@ void single_inference() {
   trt::Timer timer;
   for (int i = 0; i < 100; i++)
   {
+    timer.start();
     auto attr = resnet->forward(cvimg(image));
     printf("score : %lf, label : %d\n", attr.confidence, attr.class_label);
     timer.stop("BATCH1");