scatter_add uses src, not other (#32307)
Summary:
using `other` kwarg gives `TypeError: scatter_add_() missing 1 required positional arguments: "src"`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32307
Differential Revision: D20076859
Pulled By: zou3519
fbshipit-source-id: dfb417c087d5be41fad02dc0b2cf0506c89b1b02
