[ALSA] sound: strlcpy is smart enough

strlcpy already accounts for the trailing zero in its length
computation, so there is no need to substract one to the buffer size.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>