ASoC: core: Replace sprintf() with sysfs_emit()

For sysfs outputs, it's safer to use a new helper, sysfs_emit(),
instead of the raw sprintf() & co.  This patch replaces the sprintf()
usage straightforwardly with a new helper, sysfs_emit().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20220801170108.26340-7-tiwai@suse.de


Signed-off-by: Mark Brown <broonie@kernel.org>