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

@@ -476,6 +476,7 @@ def run(data=ROOT / 'data/coco128.yaml',  # 'dataset.yaml path'
 
     # Finish
     f = [str(x) for x in f if x]  # filter out '' and None
+    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]}"