fix stray compiler errors after rebasing

src/shims/io_error.rs

@@ -141,7 +141,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         interp_ok(Scalar::from_i32(-1))
     }
 
-    /// Sets the last OS error and return `-1` as a `i32`-typed Scalar
+    /// Sets the last OS error and return `-1` as a `i64`-typed Scalar
     fn set_last_error_and_return_i64(
         &mut self,
         err: impl Into<IoError>,

src/shims/unix/fd.rs

@@ -562,7 +562,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
     fn fd_not_found<T: From<i32>>(&mut self) -> InterpResult<'tcx, T> {
         let this = self.eval_context_mut();
         this.set_last_error(LibcError("EBADF"))?;
-        Ok((-1).into())
+        interp_ok((-1).into())
     }
 
     /// Read data from `fd` into buffer specified by `buf` and `count`.

src/shims/unix/fs.rs

@@ -1411,7 +1411,8 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         // Reject if isolation is enabled.
         if let IsolatedOp::Reject(reject_with) = this.machine.isolated_op {
             this.reject_in_isolation("`readlink`", reject_with)?;
-            return this.set_last_error_and_return_i64(LibcError("EACCES"));
+            this.set_last_error(LibcError("EACCES"))?;
+            return interp_ok(-1);
         }
 
         let result = std::fs::read_link(pathname);
@@ -1432,7 +1433,10 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
                 this.write_bytes_ptr(buf, path_bytes.iter().copied())?;
                 interp_ok(path_bytes.len().try_into().unwrap())
             }
-            Err(e) => this.set_last_error_and_return_i64(e),
+            Err(e) => {
+                this.set_last_error(e)?;
+                interp_ok(-1)
+            }
         }
     }