Remove confusing SHARD_NUMBER resetting logic (#65701)
Summary:
The SHARD_NUMBER reset was to figure out a way to differentiate whether we had just one shard vs multiple.
We shouldn't reset SHARD_NUMBER but instead should just pass and use NUM_TEST_SHARDS for clarity and ease of scaling up to more shards.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65701
Reviewed By: driazati
Differential Revision: D31209306
Pulled By: janeyx99
fbshipit-source-id: 3a3504bd47e655d62aa0d9ed2f4657ca34c71c0e
