ACPI / container: Fix error code path in container_device_attach()

To avoid leaking memory on errors from device_register(), do a
put_device() on the device object in question in the error code
path of container_device_attach().

Fixes: caa73ea1

 (ACPI / hotplug / driver core: Handle containers in a special way)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>