ksud: fix /debug_ramdisk not mounting

Use mount::mount_tmpfs() which was brought back in
bff23c6
to allow both legacy and new implementations.

This fixes /debug_ramdisk not mounting for certain devices on magic
mount.

Reference to original usage in KernelSU:
https://github.com/tiann/KernelSU/blob/69f31abd62e4f275bb33c9b478961d09231f154d/userspace/ksud/src/init_event.rs#L194

userspace/ksud/src/init_event.rs

@@ -1,9 +1,8 @@
-use crate::defs::{KSU_MOUNT_SOURCE, NO_MOUNT_PATH, NO_TMPFS_PATH, TEMP_DIR};
+use crate::defs::{NO_MOUNT_PATH, NO_TMPFS_PATH, TEMP_DIR};
 use crate::module::{handle_updated_modules, prune_modules};
-use crate::{assets, defs, ksucalls, restorecon, utils};
+use crate::{assets, defs, ksucalls, mount, restorecon, utils};
 use anyhow::{Context, Result};
 use log::{info, warn};
-use rustix::fs::{mount, MountFlags};
 use std::path::Path;
 
 pub fn on_post_data_fs() -> Result<()> {
@@ -69,7 +68,7 @@ pub fn on_post_data_fs() -> Result<()> {
 
     // mount temp dir
     if !Path::new(NO_TMPFS_PATH).exists() {
-        if let Err(e) = mount(KSU_MOUNT_SOURCE, TEMP_DIR, "tmpfs", MountFlags::empty(), "") {
+        if let Err(e) = mount::mount_tmpfs(TEMP_DIR) {
             warn!("do temp dir mount failed: {}", e);
         }
     } else {

userspace/ksud/src/main.rs

@@ -9,6 +9,7 @@ mod ksucalls;
 #[cfg(target_os = "android")]
 mod magic_mount;
 mod module;
+mod mount;
 mod profile;
 mod restorecon;
 mod sepolicy;