Rename 'labels' to 'instances' (#9066)

* Rename labels to instances

* Rename labels to instances

* align val

val.py

@@ -186,7 +186,7 @@ def run(
     if isinstance(names, (list, tuple)):  # old format
         names = dict(enumerate(names))
     class_map = coco80_to_coco91_class() if is_coco else list(range(1000))
-    s = ('%20s' + '%11s' * 6) % ('Class', 'Images', 'Labels', 'P', 'R', 'mAP@.5', 'mAP@.5:.95')
+    s = ('%22s' + '%11s' * 6) % ('Class', 'Images', 'Instances', 'P', 'R', 'mAP@.5', 'mAP@.5:.95')
     dt, p, r, f1, mp, mr, map50, map = (Profile(), Profile(), Profile()), 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
     loss = torch.zeros(3, device=device)
     jdict, stats, ap, ap_class = [], [], [], []
@@ -270,7 +270,7 @@ def run(
     nt = np.bincount(stats[3].astype(int), minlength=nc)  # number of targets per class
 
     # Print results
-    pf = '%20s' + '%11i' * 2 + '%11.3g' * 4  # print format
+    pf = '%22s' + '%11i' * 2 + '%11.3g' * 4  # print format
     LOGGER.info(pf % ('all', seen, nt.sum(), mp, mr, map50, map))
     if nt.sum() == 0:
         LOGGER.warning(f'WARNING: no labels found in {task} set, can not compute metrics without labels ⚠️')