io: rename buffer to file in doc-test
@@ -353,9 +353,9 @@ cfg_io_util! {
///
/// #[tokio::main]
/// async fn main() -> io::Result<()> {
- /// let mut buffer = File::create("foo.txt").await?;
+ /// let mut file = File::create("foo.txt").await?;
///
- /// buffer.write_all(b"some bytes").await?;
+ /// file.write_all(b"some bytes").await?;
/// Ok(())
/// }
/// ```
