[Bug] Fix edge exclusion still not working for full neighbor sampling (#3424)

python/dgl/dataloading/dataloader.py

@@ -386,7 +386,7 @@ class BlockSampler(object):
 
             # Removing edges from the frontier for link prediction training falls
             # into the category of frontier postprocessing
-            if not self.exclude_edges_in_frontier:
+            if not self.exclude_edges_in_frontier(g):
                 eid_excluder = _create_eid_excluder(exclude_eids, self.output_device)
                 if eid_excluder is not None:
                     frontier = eid_excluder(frontier)

python/dgl/dataloading/neighbor.py

@@ -165,3 +165,7 @@ class MultiLayerFullNeighborSampler(MultiLayerNeighborSampler):
     """
     def __init__(self, n_layers, return_eids=False):
         super().__init__([None] * n_layers, return_eids=return_eids)
+
+    @classmethod
+    def exclude_edges_in_frontier(cls, g):
+        return False