Refactor hackfmt main to have only one Logger.exit call
Summary:
Some refactoring I did while investigating the problem that led to
D9011103. When I originally added this logging, I wasn't sure how to do this nicely because I was not so conscious of the fact that `try` is an expression.
Note that this causes us to log 0 for the exit code of a successful exit rather than null. This seems like an improvement to me.
Reviewed By: arxanas
Differential Revision:
D9351400
fbshipit-source-id:
5a990820bd5b5dfa8cde9b2b38806341638cfccf