[Misc] Revert un-related change in #6447. (#6454)

Co-authored-by: Ubuntu <ubuntu@ip-172-31-28-63.ap-northeast-1.compute.internal>

examples/sampling/graphbolt/link_prediction.py

@@ -301,9 +301,9 @@ def train(args, graph, features, train_set, valid_set, model):
                 break
 
     # Evaluate the model.
-    # print("Validation")
-    # valid_mrr = evaluate(args, graph, features, valid_set, model)
-    # print(f"Valid MRR {valid_mrr.item():.4f}")
+    print("Validation")
+    valid_mrr = evaluate(args, graph, features, valid_set, model)
+    print(f"Valid MRR {valid_mrr.item():.4f}")
 
 
 def parse_args():
@@ -354,11 +354,8 @@ def main(args):
 
     # Model training.
     print("Training...")
-    import time
-
-    s = time.perf_counter()
     train(args, graph, features, train_set, valid_set, model)
-    print(f"{time.perf_counter() - s} seconds elpased. ")
+
     # Test the model.
     print("Testing...")
     test_set = dataset.tasks[0].test_set