Exit code not properly logged in error message

Describe the bug

If a watched replica exits due to a non-zero exit code, Tye logs an error message but does not properly include the exit code.

To Reproduce

1. Start a Tye application in "watch" mode.
2. Kill one of the replica processes.
3. Note watch: Exited with error code Microsoft.Tye.ProcessResult message.

Further technical details

The bug is here; only the ExitCode property should be logged, not the whole ProcessResult.