Fix bug scalar (#5950)

* fix bug scalar

* add test
Co-authored-by: Noneflow-ci-bot <69100618+oneflow-ci-bot@users.noreply.github.com>

python/oneflow/framework/tensor_str.py

@@ -133,7 +133,7 @@ class _Formatter(object):
 
 
 def _scalar_str(self, formatter1):
-    return formatter1.format(self.tolist())
+    return formatter1.format(_try_convert_to_local_tensor(self).tolist())
 
 
 def _vector_str(self, indent, summarize, formatter1):

python/oneflow/test/modules/test_tensor_str.py

@@ -109,6 +109,7 @@ def _test_consistent_tensor_str(test_case, device):
     x = flow.ones((10, 10), placement=placement, sbp=[flow.sbp.partial_sum])
     tensor_str = str(x)
     test_case.assertTrue("1." in tensor_str)
+    test_case.assertTrue("1." in str(x[0][0]))
 
     # summarized consistent tensor
     x = flow.ones((100, 100), placement=placement, sbp=[flow.sbp.split(0)])