Fix set_device_map docs (#53508)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53508
closes #53501
Differential Revision: D26885263
Test Plan: Imported from OSS
Reviewed By: H-Huang
Pulled By: mrshenli
fbshipit-source-id: dd0493e6f179d93b518af8f082399cacb1c7cba6
