[quant][refactor] Minor refactor of some typos (#50304)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50304
Does not include any functional changes -- purely for fixing minor typos in the `fuser_method_mappings.py`
Test Plan: Imported from OSS
Reviewed By: jerryzh168
Differential Revision: D25857248
Pulled By: z-a-f
fbshipit-source-id: 3f9b864b18bda8096e7cd52922dc21be64278887
