[float8] fix typo in bitwise_identical unit test (pytorch#918)

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test/float8/test_base.py

@@ -56,7 +56,7 @@
 is_cuda_8_9 = torch.cuda.is_available() and torch.cuda.get_device_capability() >= (8, 9)
 
 def bitwise_identical(a: Float8Tensor, b: Float8Tensor) -> bool:
-    assert torch.all(a._data == b._data).item(), "scales are not identical"
+    assert torch.all(a._scale == b._scale).item(), "scales are not identical"
     assert torch.all(a._data == b._data).item(), "data is not identical"
     return True