Fix GPU tests because of missing .cpu()

[sdesrozis]

Related to #2490

Description:

Missing cpu() to use numpy() on Tensors

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

@sdesrozis can you push the branch to origin and thus run GPU tests. It wont run on your fork

[sdesrozis]

You mean I create a branch in the ignite repo and I push the fix inside ? Or maybe there is a smarter way to do that using a relevant git command line ?

[vfdev-5]

yes, just do the following, assuming the origin points to https://github.com/pytorch/ignite

git push origin fix_gpu_precision_recall_curve

[sdesrozis]

It seems I can't rerun workflow from CircleCI...

[vfdev-5]

Let's skip circle ci, if Run unit tests on GPUs / gpu-tests (push) passes we can merge this PR.

[vfdev-5]

@sdesrozis tests are stuck on tests/ignite/contrib/metrics/test_precision_recall_curve.py::test_distrib_nccl_gpu
I'll rerun it to see if it is real

[vfdev-5]

Looks like real. I'll cancel the job and check later what happens.