Avoid combining smart pointers and qobject parent ownership

Devices are stored as QSharedPointer<Device> mDevices. If something has
the memory managed explicitly we don't want QObject parents to also try
and do the same job.

BUG: 439192
3 jobs for !11 with work/crash_fix in 2 minutes and 57 seconds (queued for 3 seconds)
latest merge request