Fix zero-export handling with `if any(f):` (#6569)

* Fix zero-export handling with `if any(f):`

Partial fix for https://github.com/ultralytics/yolov5/issues/6563

* Cleanup

export.py

@@ -476,12 +476,13 @@ def run(data=ROOT / 'data/coco128.yaml',  # 'dataset.yaml path'
 
     # Finish
     f = [str(x) for x in f if x]  # filter out '' and None
-    LOGGER.info(f'\nExport complete ({time.time() - t:.2f}s)'
-                f"\nResults saved to {colorstr('bold', file.parent.resolve())}"
-                f"\nDetect:          python detect.py --weights {f[-1]}"
-                f"\nPyTorch Hub:     model = torch.hub.load('ultralytics/yolov5', 'custom', '{f[-1]}')"
-                f"\nValidate:        python val.py --weights {f[-1]}"
-                f"\nVisualize:       https://netron.app")
+    if any(f):
+        LOGGER.info(f'\nExport complete ({time.time() - t:.2f}s)'
+                    f"\nResults saved to {colorstr('bold', file.parent.resolve())}"
+                    f"\nDetect:          python detect.py --weights {f[-1]}"
+                    f"\nPyTorch Hub:     model = torch.hub.load('ultralytics/yolov5', 'custom', '{f[-1]}')"
+                    f"\nValidate:        python val.py --weights {f[-1]}"
+                    f"\nVisualize:       https://netron.app")
     return f  # return list of exported files/dirs