Fix flaky tests for test_laop_4

[piyushghai]

Description

Fix for issue #11721 -- Removing fixed seed as the flakiness is not reproducible.

Ran tests/python/unittest/test_operator.py:test_laop_4
and tests/python/gpu/test_operator_gpu.py:test_laop_4 for 100k times each.

Checklist

Essentials

Please feel free to remove inapplicable items for your PR.

• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage:
• Unit tests are added for small changes to verify correctness (e.g. adding a new operator)
• Nightly tests are added for complicated/long-running ones (e.g. changing distributed kvstore)
• Build tests will be added for build configuration changes (e.g. adding a new build option with NCCL)
• Code is well-documented:
• For user-facing API changes, API doc string has been updated.
• For new C++ functions in header files, their functionalities and arguments are documented.
• For new examples, README.md is added to explain the what the example does, the source of the dataset, expected performance on test set and reference to the original paper if applicable
• Check the API doc at http://mxnet-ci-doc.s3-accelerate.dualstack.amazonaws.com/PR-$PR_ID/$BUILD_ID/index.html
• To the my best knowledge, examples are either not affected by this change, or have been fixed to be compatible with this change

Changes

• Remove fixed seed for test_operator:test_laop_4

Comments

CPU Run :

MXNET_TEST_COUNT=100000 nosetests --verbose -s tests/python/unittest/test_operator.py:test_laop_4
/home/ubuntu/anaconda3/lib/python3.6/site-packages/h5py/__init__.py:36: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`.
  from ._conv import register_converters as _register_converters
/home/ubuntu/anaconda3/lib/python3.6/site-packages/nose/util.py:453: DeprecationWarning: inspect.getargspec() is deprecated, use inspect.signature() or inspect.getfullargspec()
  inspect.getargspec(func)
[INFO] Setting module np/mx/python random seeds, use MXNET_MODULE_SEED=1373040982 to reproduce.
test_operator.test_laop_4 ... ok

----------------------------------------------------------------------
Ran 1 test in 326.522s

OK

GPU Run :

MXNET_TEST_COUNT=100000 nosetests --verbose -s tests/python/gpu/test_operator_gpu.py:test_laop_4
/home/ubuntu/anaconda3/lib/python3.6/site-packages/h5py/__init__.py:36: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`.
  from ._conv import register_converters as _register_converters
/home/ubuntu/anaconda3/lib/python3.6/site-packages/nose/util.py:453: DeprecationWarning: inspect.getargspec() is deprecated, use inspect.signature() or inspect.getfullargspec()
  inspect.getargspec(func)
[INFO] Setting module np/mx/python random seeds, use MXNET_MODULE_SEED=744130112 to reproduce.
test_operator_gpu.test_laop_4 ... ok

----------------------------------------------------------------------
Ran 1 test in 141.262s

[piyushghai]

@marcoabreu Can you merge this ?