Prevent final val if val=False (#16776)

Co-authored-by: UltralyticsAssistant <web@ultralytics.com>

ultralytics/utils/autobatch.py

@@ -1,6 +1,7 @@
 # Ultralytics YOLO 🚀, AGPL-3.0 license
 """Functions for estimating the best YOLO batch size to use a fraction of the available CUDA memory in PyTorch."""
 
+import os
 from copy import deepcopy
 
 import numpy as np
@@ -57,7 +58,7 @@ def autobatch(model, imgsz=640, fraction=0.60, batch_size=DEFAULT_CFG.batch):
 
     # Inspect CUDA memory
     gb = 1 << 30  # bytes to GiB (1024 ** 3)
-    d = str(device).upper()  # 'CUDA:0'
+    d = f"CUDA:{os.getenv('CUDA_VISIBLE_DEVICES', '0').strip()[0]}"  # 'CUDA:0'
     properties = torch.cuda.get_device_properties(device)  # device properties
     t = properties.total_memory / gb  # GiB total
     r = torch.cuda.memory_reserved(device) / gb  # GiB reserved