Updating submodules
Summary:
GitHub commits:
https://github.com/facebook/fbthrift/commit/fd8771904e8b12047142e0012bf843fa7540704b
https://github.com/facebook/litho/commit/6bf51e234f6fe4dca00a1769dfeca6b5f9463f27
https://github.com/facebook/rocksdb/commit/6380df5e10a1fe91ad0e7cac233b4de5ffc4a383
https://github.com/pytorch/fbgemm/commit/696c2a235959d0c3df86d0aa2f385b65d7b9cd4c
Test Plan: n/a
Reviewed By: zpao
fbshipit-source-id: 188670fcdc50ccf060eea137698ecfb45484e059
