Initialize Caffe2 only when running Caffe2 benchmarks (#19980)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19980
ghimport-source-id: ca31ca25b88a1c6219e4a32483f70738a8fdbf88
Differential Revision: D15229797
Pulled By: ilia-cher
fbshipit-source-id: 0b23dbdba0c0f60932a75d8b1900c54285f5a8e4
