rust: init: use #[default_error(err)] for the initializer macros

Initializer macros should use this attribute instead of manually parsing
the macro's input. This is because the syntax is now parsed using `syn`,
which permits more complex constructs to be parsed. In addition, this
ensures that the kernel's initializer marcos will have the exact same
syntax as the ones from pin-init.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <lossin@kernel.org>

rust/kernel/init.rs

@@ -219,20 +219,12 @@ pub trait InPlaceInit<T>: Sized {
 /// [`Error`]: crate::error::Error
 #[macro_export]
 macro_rules! try_init {
-    ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
-        $($fields:tt)*
-    }) => {
-        ::pin_init::init!($(&$this in)? $t $(::<$($generics),*>)? {
-            $($fields)*
-        }? $crate::error::Error)
-    };
-    ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
-        $($fields:tt)*
-    }? $err:ty) => {
-        ::pin_init::init!($(&$this in)? $t $(::<$($generics),*>)? {
-            $($fields)*
-        }? $err)
-    };
+    ($($args:tt)*) => {
+        ::pin_init::init!(
+            #[default_error($crate::error::Error)]
+            $($args)*
+        )
+    }
 }
 
 /// Construct an in-place, fallible pinned initializer for `struct`s.
@@ -279,18 +271,10 @@ macro_rules! try_init {
 /// [`Error`]: crate::error::Error
 #[macro_export]
 macro_rules! try_pin_init {
-    ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
-        $($fields:tt)*
-    }) => {
-        ::pin_init::pin_init!($(&$this in)? $t $(::<$($generics),*>)? {
-            $($fields)*
-        }? $crate::error::Error)
-    };
-    ($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
-        $($fields:tt)*
-    }? $err:ty) => {
-        ::pin_init::pin_init!($(&$this in)? $t $(::<$($generics),*>)? {
-            $($fields)*
-        }? $err)
-    };
+    ($($args:tt)*) => {
+        ::pin_init::pin_init!(
+            #[default_error($crate::error::Error)]
+            $($args)*
+        )
+    }
 }