all: simplify handling of Errno values

src/utils/num_cpus.rs

@@ -1,17 +1,17 @@
 use {
-    crate::utils::oserror::OsError,
+    crate::utils::oserror::{OsError, OsErrorExt},
     smallvec::{SmallVec, smallvec_inline},
-    uapi::{Errno, c},
+    uapi::c,
 };
 
 #[cfg_attr(not(feature = "it"), expect(dead_code))]
 pub fn num_cpus() -> Result<u32, OsError> {
     let mut buf: SmallVec<[usize; 32]> = smallvec_inline![0; 32];
     loop {
-        match uapi::sched_getaffinity(0, &mut buf) {
+        match uapi::sched_getaffinity(0, &mut buf).to_os_error() {
             Ok(_) => return Ok(count(&buf)),
-            Err(Errno(c::EINVAL)) => buf.extend_from_slice(&[0; 32][..]),
-            Err(e) => return Err(e.into()),
+            Err(OsError(c::EINVAL)) => buf.extend_from_slice(&[0; 32][..]),
+            Err(e) => return Err(e),
         }
     }
 }