kernel, ksud, manager: New supercalls implementations

* This commit squashes new supercall impl:
3138651a38..562a3b9be7

Thanks to these people below:

Official KernelSU:
Co-authored-by: Wang Han <416810799@qq.com>
Co-authored-by: weishu <twsxtd@gmail.com>
Co-authored-by: Ylarod <me@ylarod.cn>
Co-authored-by: YuKongA <70465933+YuKongA@users.noreply.github.com>

xxKSU maintainer:
Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
MMRL maintainer:
Co-authored-by: Der_Googler <54764558+dergoogler@users.noreply.github.com>
KSUN maintainer:
Co-authored-by: Rifat Azad <33044977+rifsxd@users.noreply.github.com>
KOWSU maintainer:
Co-authored-by: KOWX712 <leecc0503@gmail.com>

kernel/ksud.c

@@ -79,6 +79,7 @@ void on_post_fs_data(void)
 	done = true;
 	pr_info("%s!\n", __func__);
 	ksu_load_allow_list();
+	ksu_observer_init();
 	// sanity check, this may influence the performance
 	stop_input_hook();
 
@@ -426,7 +427,7 @@ int ksu_handle_input_handle_event(unsigned int *type, unsigned int *code,
 	return 0;
 }
 
-bool ksu_is_safe_mode()
+bool ksu_is_safe_mode(void)
 {
 	static bool safe_mode = false;
 	if (safe_mode) {