alsa-gobject: fix indentation

alsa-project/alsa-gobject pull request #43 was opened from takaswie:

This patchset is trivial to apply fixes for 4-spaces indentation.

Request URL : https://github.com/alsa-project/alsa-gobject/pull/43 Patch URL : https://github.com/alsa-project/alsa-gobject/pull/43.patch Repository URL: https://github.com/alsa-project/alsa-gobject