Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit. Fix it by replacing with scnprintf().
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200311090644.20287-1-tiwai@suse.de
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>