Fix #1010: Avoid an empty error from a successful move.
Fix #1010: Avoid an empty error from a successful move.

Commits don't output a success flag any more, and the success callback
will only be called after a successful operation. This might change
when we address #992, but for the moment this is the expected result.

jmorse/cyanide,jmorse/cyanide,jmorse/cyanide,jmorse/cyanide