[PATCH] rust: file: use to_result for error handling

["Onur Özkan" <work@onurozkan.dev>]

Simplifies error handling by replacing the manual check
of the return value with the `to_result` helper.

Signed-off-by: Onur Özkan <work@onurozkan.dev>
---
 rust/kernel/fs/file.rs | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/rust/kernel/fs/file.rs b/rust/kernel/fs/file.rs
index 35fd5db35c46..924f01bd64c2 100644
--- a/rust/kernel/fs/file.rs
+++ b/rust/kernel/fs/file.rs
@@ -10,7 +10,7 @@
 use crate::{
     bindings,
     cred::Credential,
-    error::{code::*, Error, Result},
+    error::{code::*, to_result, Error, Result},
     types::{ARef, AlwaysRefCounted, NotThreadSafe, Opaque},
 };
 use core::ptr;
@@ -398,9 +398,8 @@ impl FileDescriptorReservation {
     pub fn get_unused_fd_flags(flags: u32) -> Result<Self> {
         // SAFETY: FFI call, there are no safety requirements on `flags`.
         let fd: i32 = unsafe { bindings::get_unused_fd_flags(flags) };
-        if fd < 0 {
-            return Err(Error::from_errno(fd));
-        }
+        to_result(fd)?;
+
         Ok(Self {
             fd: fd as u32,
             _not_send: NotThreadSafe,
--
2.50.0