!2267 Fix comment errors in graphdata

Merge pull request !2267 from heleiwang/fix_doc

mindspore/dataset/engine/graphdata.py

@@ -214,7 +214,7 @@ class GraphData:
 
         Returns:
             Dict: Meta information of the graph. The key is node_type, edge_type, node_num, edge_num,
-                node_feature_type and edge_feature_type.
+            node_feature_type and edge_feature_type.
         """
         return self._graph.graph_info()