Change startTime_ to endTime_ in FutureInfo (#30342)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30342
This can eliminate the unnecessary calls to getRPCEndTime(). Reduce lines of code for simplicity.
ghstack-source-id: 95377162
Test Plan:
# Unit tests
```
buck test mode/dev-nosan //caffe2/test:rpc_fork -- test_rpc_timeouts
buck-out/gen/caffe2/test/rpc_fork\#binary.par -r test_rpc_timeouts
```
```
buck test mode/dev-nosan //caffe2/test:rpc_fork_thrift -- test_rpc_timeouts
buck-out/gen/caffe2/test/rpc_fork_thrift\#binary.par -r test_rpc_timeouts
```
Differential Revision: D5705624
fbshipit-source-id: aca4c4917718124022c09ee0d13cf5ca483402af
