[caffe2/torch] Use logger in jit instantiator
Summary:
Previously the module would log some data using `print()`. This can be
a problem when used in contexts where the process expects to write data to
stdout itself. This diff changes the log statements to use `logger` instead.
This makes it similar to other log statements in the same module.
Test Plan:
Confirmed no weird test showed up when running:
buck test caffe2/test/distributed/nn/api:remote_module_fork
Differential Revision: D22136172
fbshipit-source-id: a3d144eba6c75925ed684981793c84b36eb45a5d
