!10430 ascend support ps cache sink_size as 1

From: @limingqi107
Reviewed-by: @chujinjin,@kisnwang
Signed-off-by: @kisnwang

mindspore/train/dataset_helper.py

@@ -99,7 +99,8 @@ def connect_network_with_dataset(network, dataset_helper):
     if (hasattr(dataset_iter, "sink_size") and dataset_iter.sink_size == 1) \
             and (hasattr(dataset_iter, "sink_count") and dataset_iter.sink_count == 1) \
             and context.get_context("device_target") == "Ascend" \
-            and context.get_context("mode") == context.GRAPH_MODE:
+            and context.get_context("mode") == context.GRAPH_MODE \
+            and ms_role != "MS_WORKER":
 
         if not hasattr(dataset, '__network__'):
             dataset.__network__ = network