Cancelling Touch ID still results in key successfully written

When I do 
```bash
keymaster set "my_test_key" "test"
```

And then press "Cancel" when Touch ID shows up, it tells me
```
"Key my_test_key has been sucessfully set in the keychain"
```

And indeed the key has been created in Keychain, but with an empty password.

---

Expected behavior: spit error message and exit with non-0 code