Get rid of a warning about implicit declaration of exp10, which is
behind _GNU_SOURCE as a non-standard feature. The same problem was fixed
for alsamixer in commit 116488e5f2.
Signed-off-by: Milton Vandersloot <miltonvandersloot@fake-box.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
When -M option is given, amixer handles the volumes in percent unit
with the mapping more intuitive to human ears just like in alsamixer.
The -R option is to take the raw value as the volume percentage.
This mode is still used as default.
Signed-off-by: Takashi Iwai <tiwai@suse.de>