Fixed a typo in dataloader.py. (#49437)
Summary:
This small PR fixes a one character typo in the docstring for `DataLoader`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49437
Reviewed By: ngimel
Differential Revision: D25665971
Pulled By: mrshenli
fbshipit-source-id: b60f975f1e3bf0bb8f88e39f490f716c602f087e
