[contrib/ASP] sparsity_is_enabled method does not exist

[sakaia]

sparsity_is_enabled method does not exist.
From seeing the code, It should be _is_sparsity_enabled. It works fine.

Error message is follows.

Traceback (most recent call last):
  File "checkpointing_test_part2.py", line 80, in <module>
    main(checkpoint['step'], args, checkpoint['model_state_dict'], checkpoint['optimizer_state_dict'])
  File "checkpointing_test_part2.py", line 54, in main
    print("Model sparsity is %s" % ("enabled" if ASP.sparsity_is_enabled() else "disabled"))
AttributeError: type object 'ASP' has no attribute 'sparsity_is_enabled'

References

• apex/contrib/sparsity/test

[ChongyuNVIDIA]

This issue is already fixed in 89edb81.