rust: opp: fix broken rustdoc link

Correct the spelling of "CString" to make the link work.

Fixes: ce32e2d ("rust: opp: Add abstractions for the configuration options")
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Author: tamird

rust/kernel/opp.rs

@@ -87,7 +87,7 @@ use core::{marker::PhantomData, ptr};
 
 use macros::vtable;
 
-/// Creates a null-terminated slice of pointers to [`Cstring`]s.
+/// Creates a null-terminated slice of pointers to [`CString`]s.
 fn to_c_str_array(names: &[CString]) -> Result<KVec<*const u8>> {
     // Allocated a null-terminated vector of pointers.
     let mut list = KVec::with_capacity(names.len() + 1, GFP_KERNEL)?;