conf: Forbid device alias change on device-update

conf: Forbid device alias change on device-update

https://bugzilla.redhat.com/show_bug.cgi?id=1585108

When updating a live device users might pass different alias than
the one the device has. Currently, this is silently ignored which
goes against our behaviour for other parts of the device where we
explicitly allow only certain changes and error out loudly on
anything else.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>