!421 Fix no need_wrap in ge bankend in mode.train with dataset_sink

Merge pull request !421 from ghzl/fix-no-wrap-in-ge-bankend-in-train

mindspore/train/model.py

@@ -254,7 +254,8 @@ class Model:
         """
         # remove later to deal with loop sink
         need_wrap = False
-        if not hasattr(train_dataset, '__ME_INITED__') and context.get_context("enable_loop_sink"):
+        if not hasattr(train_dataset, '__ME_INITED__') and context.get_context("enable_loop_sink") \
+               and not context.get_context("enable_ge"):
             need_wrap = True
 
         dataset_helper = DatasetHelper(train_dataset)
@@ -418,7 +419,8 @@ class Model:
 
         # remove later to deal with loop sink
         need_wrap = False
-        if not hasattr(valid_dataset, '__ME_INITED__') and context.get_context("enable_loop_sink"):
+        if not hasattr(valid_dataset, '__ME_INITED__') and context.get_context("enable_loop_sink") \
+               and not context.get_context("enable_ge"):
             need_wrap = True
 
         valid_dataset.__loop_size__ = 1