According to the documentation, the tracepoint
`coin_selection:aps_create_tx_internal` "Is called when the second
`CreateTransactionInternal` with Avoid Partial Spends enabled completes."
Currently it is only called if the second call to
`CreateTransactionInternal` succeeds, i.e. the third parameter is always
`true` and we don't get notified in the case that it fails.
Fix this by introducing a boolean variable for the result of the call
and moving the tracepoint call outside the if body.