Make the "Failure info" report test name when using --distribute

[jgphpc]

Hi,

Minor issue but running a failing test (reframe/4.9.3) without --distribute will correctly report the test filename:

• reframe -r --failure-stats -c x.py

* Test file: .../x.py
* Reason: sanity error

Running the same failing test with --distribute will report this test filename:

• reframe -r --failure-stats -c x.py --distribute=idle

  * Test file: .venv_alps/pilatus/lib64/python3.11/site-packages/reframe/frontend/testgenerators.py
  * Reason: sanity error

I would expect the test filename instead of testgenerators.py