rust: pin-init: change the way the paste! macro is called

Change the paste macro path from `::kernel::macros::paste!` to use
`$crate::init::macros::paste!` instead, which links to
`::macros::paste!`. This is because the pin-init crate will be a
dependency of the kernel, so it itself cannot have the kernel as a
dependency.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-14-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: y86-dev

rust/pin-init/src/macros.rs

@@ -498,6 +498,8 @@
 //! };
 //! ```
 
+pub use ::macros::paste;
+
 /// Creates a `unsafe impl<...> PinnedDrop for $type` block.
 ///
 /// See [`PinnedDrop`] for more information.
@@ -1134,7 +1136,7 @@ macro_rules! __init_internal {
             // information that is associated to already parsed fragments, so a path fragment
             // cannot be used in this position. Doing the retokenization results in valid rust
             // code.
-            ::kernel::macros::paste!($t::$get_data())
+            $crate::init::macros::paste!($t::$get_data())
         };
         // Ensure that `data` really is of type `$data` and help with type inference:
         let init = $crate::init::__internal::$data::make_closure::<_, __InitOk, $err>(
@@ -1215,7 +1217,7 @@ macro_rules! __init_internal {
         //
         // We rely on macro hygiene to make it impossible for users to access this local variable.
         // We use `paste!` to create new hygiene for `$field`.
-        ::kernel::macros::paste! {
+        $crate::init::macros::paste! {
             // SAFETY: We forget the guard later when initialization has succeeded.
             let [< __ $field _guard >] = unsafe {
                 $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
@@ -1246,7 +1248,7 @@ macro_rules! __init_internal {
         //
         // We rely on macro hygiene to make it impossible for users to access this local variable.
         // We use `paste!` to create new hygiene for `$field`.
-        ::kernel::macros::paste! {
+        $crate::init::macros::paste! {
             // SAFETY: We forget the guard later when initialization has succeeded.
             let [< __ $field _guard >] = unsafe {
                 $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
@@ -1278,7 +1280,7 @@ macro_rules! __init_internal {
         //
         // We rely on macro hygiene to make it impossible for users to access this local variable.
         // We use `paste!` to create new hygiene for `$field`.
-        ::kernel::macros::paste! {
+        $crate::init::macros::paste! {
             // SAFETY: We forget the guard later when initialization has succeeded.
             let [< __ $field _guard >] = unsafe {
                 $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
@@ -1315,7 +1317,7 @@ macro_rules! __init_internal {
             // information that is associated to already parsed fragments, so a path fragment
             // cannot be used in this position. Doing the retokenization results in valid rust
             // code.
-            ::kernel::macros::paste!(
+            $crate::init::macros::paste!(
                 ::core::ptr::write($slot, $t {
                     $($acc)*
                     ..zeroed
@@ -1339,7 +1341,7 @@ macro_rules! __init_internal {
             // information that is associated to already parsed fragments, so a path fragment
             // cannot be used in this position. Doing the retokenization results in valid rust
             // code.
-            ::kernel::macros::paste!(
+            $crate::init::macros::paste!(
                 ::core::ptr::write($slot, $t {
                     $($acc)*
                 });