Delete "named_guard" in native_functions.yaml (#38429)
Summary:
"named_guard" is not a supported option (i.e., a typo).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38429
Differential Revision: D21572794
Pulled By: zou3519
fbshipit-source-id: 6e799611344f373b03f64410d7af9c2c89a75f55
