[benchmarks] fix torchmetrics accuracy (#5594)

benchmarks/benchmarks/model_acc/bench_rgcn_base.py

@@ -61,6 +61,11 @@ def track_acc(dataset, ns_mode):
     with torch.no_grad():
         logits = model(g)
     logits = logits[target_idx]
-    test_acc = accuracy(logits[test_idx].argmax(dim=1), labels[test_idx]).item()
+    test_acc = accuracy(
+        logits[test_idx].argmax(dim=1),
+        labels[test_idx],
+        task="multiclass",
+        num_classes=num_classes,
+    ).item()
 
     return test_acc

benchmarks/benchmarks/model_speed/bench_rgcn_base.py

@@ -3,7 +3,6 @@ import time
 import torch
 import torch.nn as nn
 import torch.nn.functional as F
-from torchmetrics.functional import accuracy
 
 from .. import rgcn, utils