xenconsoled: Remove unexpected daemonize behavior

xenconsoled: Remove unexpected daemonize behavior

Previously, xenconsoled's daemonize function would do nothing if its
parent process is init (as it is under systemd but not sysv init).
This is confusing. Instead, always daemonize when asked to, but use the
"interactive" switch when running from the systemd service.

Because a pidfile is only written when daemonizing, drop the pidfile
parameters from the service file (systemd keeps track of the pids
anyway).

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>