[PATCH v3 2/3] rust: error: Update 'stack_try_pin_init' example

[Jimmy Ostler <jtostler1@gmail.com>]

Change documentation imports to use `kernel::alloc::AllocError`,
because `KBox::new()` now returns that, instead of the 'core'
`AllocError`.

Signed-off-by: Jimmy Ostler <jtostler1@gmail.com>
---
 rust/kernel/init.rs | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 347049df556b..3d099908dbd5 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -290,9 +290,16 @@ macro_rules! stack_pin_init {
 ///
 /// ```rust,ignore
 /// # #![expect(clippy::disallowed_names)]
-/// # use kernel::{init, pin_init, stack_try_pin_init, init::*, sync::Mutex, new_mutex};
+/// # use kernel::{init,
+/// #   pin_init,
+/// #   stack_try_pin_init,
+/// #   init::*,
+/// #   sync::Mutex,
+/// #   new_mutex,
+/// #   alloc::AllocError
+/// # };
 /// # use macros::pin_data;
-/// # use core::{alloc::AllocError, pin::Pin};
+/// # use core::pin::Pin;
 /// #[pin_data]
 /// struct Foo {
 ///     #[pin]
@@ -316,9 +323,16 @@ macro_rules! stack_pin_init {
 ///
 /// ```rust,ignore
 /// # #![expect(clippy::disallowed_names)]
-/// # use kernel::{init, pin_init, stack_try_pin_init, init::*, sync::Mutex, new_mutex};
+/// # use kernel::{init,
+/// #   pin_init,
+/// #   stack_try_pin_init,
+/// #   init::*,
+/// #   sync::Mutex,
+/// #   new_mutex,
+/// #   alloc::AllocError
+/// # };
 /// # use macros::pin_data;
-/// # use core::{alloc::AllocError, pin::Pin};
+/// # use core::pin::Pin;
 /// #[pin_data]
 /// struct Foo {
 ///     #[pin]
-- 
2.47.1