[GraphBolt] Fix fanouts setting in rgcn example (#6959)

examples/sampling/graphbolt/rgcn/hetero_rgcn.py

@@ -430,6 +430,7 @@ def evaluate(
     else:
         evaluator = MAG240MEvaluator()
 
+    num_etype = len(g.num_edges)
     data_loader = create_dataloader(
         name,
         g,
@@ -437,7 +438,7 @@ def evaluate(
         item_set,
         device,
         batch_size=4096,
-        fanouts=[25, 10],
+        fanouts=[torch.full((num_etype,), 25), torch.full((num_etype,), 10)],
         shuffle=False,
         num_workers=num_workers,
     )
@@ -491,6 +492,7 @@ def train(
     print("Start to train...")
     category = "paper"
 
+    num_etype = len(g.num_edges)
     data_loader = create_dataloader(
         name,
         g,
@@ -498,7 +500,7 @@ def train(
         train_set,
         device,
         batch_size=1024,
-        fanouts=[25, 10],
+        fanouts=[torch.full((num_etype,), 25), torch.full((num_etype,), 10)],
         shuffle=True,
         num_workers=num_workers,
     )