rust: factory: Add rros_release_element function

Diff:
1. In factory.rs:
  - Change the field `inside` and `dispose` in struct `RrosFactory`.
  - Implement methods  `remove_element_device`, `is_public`,
    `__do_put_element`, `do_put_element_work`, `do_put_element_irq`,
    `do_put_element`, `put_element` for `RrosElement`
  - Modify the code used `inside`, because type has changed from `Option<RrosFactoryInside>` to
    `RrosFactoryInside`.
  - Add function `unbind_file_to_element`
  - Add function `rros_open_element` and `rros_release_element`
2. In sub factory(proxy/buf/poll,etc. .rs):
  Change the static factory creation.
3. In device.rs: Implement `unregister` for `Device`
4. In type.rs: Implement `hash_del` for `HlistNode`

Status:
1. Compilation: Compile with clang-13.0.1 toolchain, `ARCH=arm64`,
  use `rros_defconfig`.
2. Functional test: Haven't started yet.
3. Eliminate warnings in factory.rs, most of them are dead_code warnings.

Author: yexuanyang

kernel/rros/clock.rs

@@ -546,7 +546,7 @@ pub static mut RROS_CLOCK_FACTORY: SpinLock<factory::RrosFactory> = unsafe {
         dispose: Some(clock_factory_dispose),
         attrs: None, //sysfs::attribute_group::new(),
         flags: factory::RrosFactoryType::Invalid,
-        inside: Some(factory::RrosFactoryInside {
+        inside: factory::RrosFactoryInside {
             type_: DeviceType::new(),
             class: None,
             cdev: None,
@@ -559,7 +559,7 @@ pub static mut RROS_CLOCK_FACTORY: SpinLock<factory::RrosFactory> = unsafe {
             name_hash: None,
             hash_lock: None,
             register: None,
-        }),
+        },
     })
 };
 
@@ -1028,7 +1028,7 @@ impl FileOperations for ClockOps {
     }
 }
 
-pub fn clock_factory_dispose(ele: factory::RrosElement) {}
+pub fn clock_factory_dispose(ele: &mut factory::RrosElement) {}
 
 fn timer_needs_enqueuing(timer: *mut RrosTimer) -> bool {
     unsafe {

kernel/rros/control.rs

@@ -28,7 +28,7 @@ pub static mut RROS_CONTROL_FACTORY: SpinLock<RrosFactory> = unsafe {
         dispose: None,
         attrs: None,
         flags: crate::factory::RrosFactoryType::SINGLE,
-        inside: Some(RrosFactoryInside {
+        inside: RrosFactoryInside {
             type_: DeviceType::new(),
             class: None,
             cdev: None,
@@ -41,7 +41,7 @@ pub static mut RROS_CONTROL_FACTORY: SpinLock<RrosFactory> = unsafe {
             name_hash: None,
             hash_lock: None,
             register: None,
-        }),
+        },
     })
 };