alsactl: init command now honors -g flag as well

alsa-project/alsa-utils pull request #80 was opened from MichaIng:

As of #75 this commit aligns the manpage with the new behaviour.

Request URL : https://github.com/alsa-project/alsa-utils/pull/80 Patch URL : https://github.com/alsa-project/alsa-utils/pull/80.patch Repository URL: https://github.com/alsa-project/alsa-utils