inductor: fix name 'inf' is not defined issue when calling external_call function (#101865)
This PR will fix https://github.com/pytorch/pytorch/issues/101695.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/101865
Approved by: https://github.com/jgong5, https://github.com/desertfire, https://github.com/Skylion007
