hw/qdev: Abort rather than ignoring errors adding device properties

Instead of ignoring any errors that occur when adding properties
to a new device in device_initfn(), check for them and abort if any
occur. The most likely cause is accidentally adding a duplicate
property, which is a programming error by the device author.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1364217314-7400-3-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
