message: Fix update_op_dependencies_test for TF v2
  Summary:
  Use namespace on while_loop to ensure that the names
  are the same from V1 to V2.
  Manifest Task: T10908
  Test Plan: all tests ok
  Reviewers: #tensorflow, georgep
diff: @@ -183,7 +183,7 @@ class UpdateOpDependenciesTest(xla_test.XLATestCase):
  return (i, x, y)
  i = 0
  - return control_flow_ops.while_loop(cond, body, (i, x, x))[1:]
  + return control_flow_ops.while_loop(cond, body, (i, x, x), name='')[1:]
  with ops.device('cpu'):
  x = array_ops.placeholder(np.float32, [4])
  @@ -206,8 +206,8 @@ class UpdateOpDependenciesTest(xla_test.XLATestCase):
  cs_list = tu.get_compute_sets_from_report(s)
  ok = [
  - '__seed*', 'Copy_*_to_*', 'while/Tanh/tanh*/Op/Tanh',
  - 'while/Tanh_1/tanh*/Op/Tanh'
  + '__seed*', 'Copy_*_to_*', 'Tanh/tanh*/Op/Tanh',
  + 'Tanh_1/tanh*/Op/Tanh'
  ]
  self.assertTrue(tu.check_all_compute_sets_and_list(cs_list, ok))
  