[Minor] Remove dead code in RolloutFromModel

[ianbarber]

Description

Removing what looks like some leftover debug code, happens after a non-conditional return statement so cannot be executed.

Motivation and Context

Purely a cleanup, observed when reading through the code.

• I have raised an issue to propose this change (required for new features and bug fixes)

Types of changes

What types of changes does your code introduce? Remove all that do not apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds core functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Example (update in the folder of examples)

Checklist

Go over all the following points, and put an x in all the boxes that apply.
If you are unsure about any of these, don't hesitate to ask. We are here to help!

• [ x] I have read the CONTRIBUTION guide (required)
• My change requires a change to the documentation.
• I have updated the tests accordingly (required for a bug fix or a new feature).
• I have updated the documentation accordingly.

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/rl/1752

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

✅ You can merge normally! (8 Unrelated Failures)

As of commit 3be7f3a with merge base 0e02132 ():

FLAKY - The following jobs failed but were likely due to flakiness present on trunk:

• Build M1 Wheels / pytorch/rl / wheel-py3_8-cpu (gh)
  ImportError: cannot import name 'MemoryMappedTensor' from 'tensordict' (/Users/ec2-user/runner/_work/_temp/conda_environment_7258834162/lib/python3.8/site-packages/tensordict/__init__.py)
• Continuous Benchmark (PR) / CPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Continuous Benchmark (PR) / GPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Unit-tests on MacOS CPU / tests (3.8) / macos-job (gh)
  test/test_libs.py::TestGym::test_vecenvs_env[CartPole-v1]
• Unit-tests on Windows CPU / unittests / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 128

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• Habitat Tests on Linux / tests (3.9, 11.6) / linux-job (gh)
  test/test_libs.py::TestHabitat::test_habitat_render[False-HabitatPick-v0]
• RLHF Tests on Linux / unittests (3.9, 12.1) / linux-job (gh)
  test/test_rlhf.py::TestRollout::test_rollout_from_data
• Unit-tests on Windows GPU / unittests / windows-job (gh)
  Process completed with exit code 1.

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[vmoens]

LGTM thanks for this!

[vmoens]

Note: The RLHF CI is broken bc our file format has changed and the artifacts are not compatible anymore - will fix this today