qobject_to_qfloat() and qobject_to_qint() crash on null, which is a
trap for the unwary. Return null instead, and simplify a few callers.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1444918537-18107-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>