alsa-gobject: seq/timer: use (inout) annotation for API to retrieve status

alsa-project/alsa-gobject pull request #38 was opened from takaswie:

It's probable to retrieve status for something several times in runtime, and it's convenient for the runtime to use pre-allocated instance for the status.

Request URL : https://github.com/alsa-project/alsa-gobject/pull/38 Patch URL : https://github.com/alsa-project/alsa-gobject/pull/38.patch Repository URL: https://github.com/alsa-project/alsa-gobject