amixer: cset: check control is readable before reading it

[GitHub pull_request - opened]

alsa-project/alsa-utils pull request #63 was opened from ViorelSuman:

In current implementation cset command will fail on
controls which are not readable, ie just writable.
Check readable state prior calling snd_ctl_elem_read.

Signed-off-by: Viorel Suman <viorel.suman at nxp.com>

Request URL   : https://github.com/alsa-project/alsa-utils/pull/63
Patch URL     : https://github.com/alsa-project/alsa-utils/pull/63.patch
Repository URL: https://github.com/alsa-project/alsa-utils