Fix #16261 (#16266)

- this PR should close #16261 
- fixes #16261

Confirmed to build with Rust-1.86 and to yield a working binary.

crates/nu-system/src/netbsd.rs

@@ -100,6 +100,8 @@ unsafe fn sysctl_get(
     data: *mut libc::c_void,
     data_len: *mut usize,
 ) -> i32 {
+    // Safety: Call to unsafe function `libc::sysctl`
+    unsafe {
         sysctl(
             name,
             name_len,
@@ -113,6 +115,7 @@ unsafe fn sysctl_get(
             0,
         )
     }
+}
 
 fn get_procs() -> io::Result<Vec<KInfoProc>> {
     // To understand what's going on here, see the sysctl(3) and sysctl(7) manpages for NetBSD.
@@ -249,6 +252,8 @@ fn get_proc_args(pid: i32, what: i32) -> io::Result<Vec<u8>> {
 
 // For getting simple values from the sysctl interface
 unsafe fn get_ctl<T>(ctl_name: &[i32]) -> io::Result<T> {
+    // Safety: Call to unsafe function `netbsd::sysctl_get`
+    unsafe {
         let mut value: MaybeUninit<T> = MaybeUninit::uninit();
         let mut value_len = mem::size_of_val(&value);
         check(sysctl_get(
@@ -259,6 +264,7 @@ unsafe fn get_ctl<T>(ctl_name: &[i32]) -> io::Result<T> {
         ))?;
         Ok(value.assume_init())
     }
+}
 
 fn get_pagesize() -> io::Result<libc::c_int> {
     // not in libc for some reason