Revert D22519869: [pytorch][PR] RandomSampler generates samples one at a time when replacement=True
Test Plan: revert-hammer
Differential Revision:
D22519869 (https://github.com/pytorch/pytorch/commit/09647e1287f4490b4ef3ada2d34c1f9a82b342e9)
Original commit changeset: be6585002586
fbshipit-source-id: 31ca5ceb24dd0b291f46f427a6f30f1037252a5d
