Panic on exit

[bloznelis]

Sometimes on app exit this is printed out:

π ~ :: kbt
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: ()', src/linux.rs:29:22
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
bye!

Either handle it or suppress it, but this shouldn't be shown to user.