[PATCH 2/2] rust: alloc: use unsafe_precondition_assert! in Vec length helpers

[JX]

Vec::inc_len and Vec::dec_len are unsafe functions whose debug
assertions directly check their documented safety preconditions.

Use unsafe_precondition_assert! for these checks so violations are
identified as unsafe precondition failures. The inc_len use also keeps
the const-compatible macro path covered by kernel compilation.

Suggested-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Link: https://github.com/Rust-for-Linux/linux/issues/1232
Signed-off-by: JX <1239989762@xxxxxx>
---
 rust/kernel/alloc/kvec.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs
index c7546b9da4..9216a4a304 100644
--- a/rust/kernel/alloc/kvec.rs
+++ b/rust/kernel/alloc/kvec.rs
@@ -23,7 +23,8 @@
     page::{
         AsPageIter,
         PAGE_SIZE, //
-    }, //
+    },
+    unsafe_precondition_assert, //
 };
 
 use core::{
@@ -230,7 +231,7 @@ pub const fn len(&self) -> usize {
     #[inline]
     pub const unsafe fn inc_len(&mut self, additional: usize) {
         // Guaranteed by the type invariant to never underflow.
-        debug_assert!(additional <= self.capacity() - self.len());
+        unsafe_precondition_assert!(additional <= self.capacity() - self.len());
         // INVARIANT: By the safety requirements of this method this represents the exact number of
         // elements stored within `self`.
         self.len += additional;
@@ -245,7 +246,7 @@ pub const fn len(&self) -> usize {
     ///
     /// - `count` must be less than or equal to `self.len`.
     unsafe fn dec_len(&mut self, count: usize) -> &mut [T] {
-        debug_assert!(count <= self.len());
+        unsafe_precondition_assert!(count <= self.len());
         // INVARIANT: We relinquish ownership of the elements within the range `[self.len - count,
         // self.len)`, hence the updated value of `set.len` represents the exact number of elements
         // stored within `self`.
-- 
2.54.0