message: Fix conv_graph_caching_test compute set name.
  Test Plan: //tensorflow/compiler/plugin/poplar:conv_graph_caching_test passes
  Reviewers: #tensorflow, davidn
diff: @@ -98,7 +98,6 @@ class ConvGraphCachingTest(test_util.TensorFlowTestCase):
  # Matches two convolutions
  ok = [
  '__seed*', 'Copy_*weightsRearranged', 'host-exchange-local-copy-',
  - 'Copy_vs/conv2d_1/Conv2D/convolution.7/Conv_1x1/cast_',
  'vs/conv2d/Conv2D/convolution.*/Conv_1x1', 'vs/Cast/convert.*/Cast',
  'vs/conv2d_1/Conv2D/convolution.*/Conv_1x1'
  ]
  