platform/x86: classmate-laptop: Replace snprintf in show functions with sysfs_emit

show() must not use snprintf() when formatting the value to be
returned to user space.

Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
Link: https://lore.kernel.org/r/20241019054426.8182-1-zenghongling@kylinos.cn


[ij: Added linux/sysfs.h include]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>