audio: set return value in adev_set_voice_volume to zero
audio: set return value in adev_set_voice_volume to zero

Google's Android VTS tests expect a zero return value from the
adev_set_voice_volume() function if the gain value is [0.0 - 1.0].

Set the return value in the adev_set_voice_volume() function to zero.

Change-Id: I6a048a41d3e47267cd5fdca9d597659e7620f863
Signed-off-by: Maksym Prymierov <e05afb7aaf4851a33b3022ff2eecb9820c1f1f8f@globallogic.com>

CirrusLogic/tinyhal,CirrusLogic/tinyhal,CirrusLogic/tinyhal