Rustify Sys::open and some fs:: error handling.

src/header/stdlib/mod.rs

@@ -10,6 +10,7 @@ use rand_xorshift::XorShiftRng;
 
 use crate::{
     c_str::CStr,
+    error::ResultExt,
     fs::File,
     header::{
         ctype,
@@ -673,12 +674,14 @@ pub unsafe extern "C" fn mkostemps(
     suffix_len: c_int,
     mut flags: c_int,
 ) -> c_int {
+    // TODO: Rustify impl
+
     flags &= !O_ACCMODE;
     flags |= O_RDWR | O_CREAT | O_EXCL;
 
     inner_mktemp(name, suffix_len, || {
         let name = CStr::from_ptr(name);
-        let fd = Sys::open(name, flags, 0o600);
+        let fd = Sys::open(name, flags, 0o600).or_minus_one_errno();
 
         if fd >= 0 {
             Some(fd)