[PATCH] rust: cpufreq: fix `undocumented_unsafe_blocks` in `PolicyCpu::from_cpu()`

[Miguel Ojeda <ojeda@kernel.org>]

For Rust <= 1.86, Clippy triggers after commit 02c5d7bfa872 ("rust:
cpufreq: reject NULL from cpufreq_cpu_get()"):

    warning: unsafe block missing a safety comment
       --> rust/kernel/cpufreq.rs:700:26
        |
    700 |             NonNull::new(unsafe { bindings::cpufreq_cpu_get(u32::from(cpu)) }).ok_or(ENODEV)?;
        |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = help: consider adding a safety comment on the preceding line
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks
        = note: requested on the command line with `-W clippy::undocumented-unsafe-blocks`

Thus clean it up.

Fixes: 02c5d7bfa872 ("rust: cpufreq: reject NULL from cpufreq_cpu_get()")
Assisted-by: LLM
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/cpufreq.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/rust/kernel/cpufreq.rs b/rust/kernel/cpufreq.rs
index b75d692846a2..5f5beedec88b 100644
--- a/rust/kernel/cpufreq.rs
+++ b/rust/kernel/cpufreq.rs
@@ -695,9 +695,11 @@ fn clear_data<T: ForeignOwnable>(&mut self) -> Option<T> {
 
 impl<'a> PolicyCpu<'a> {
     fn from_cpu(cpu: CpuId) -> Result<Self> {
-        // SAFETY: It is safe to call `cpufreq_cpu_get` for any valid CPU.
-        let ptr =
-            NonNull::new(unsafe { bindings::cpufreq_cpu_get(u32::from(cpu)) }).ok_or(ENODEV)?;
+        let ptr = NonNull::new(
+            // SAFETY: It is safe to call `cpufreq_cpu_get` for any valid CPU.
+            unsafe { bindings::cpufreq_cpu_get(u32::from(cpu)) },
+        )
+        .ok_or(ENODEV)?;
 
         Ok(Self(
             // SAFETY: `ptr` is non-NULL and `cpufreq_cpu_get()` took a reference on it, so it is

base-commit: 2efb7a11f1aa4d2dc285fe2680cca22cb9f72f64
-- 
2.56.0