livepatch: Replace snprintf() with sysfs_emit()

Let's use sysfs_emit() instead of snprintf().

Suggested-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20240625151123.2750-4-laoar.shao@gmail.com


Signed-off-by: Petr Mladek <pmladek@suse.com>