Take an opportunity to use Option::ok_or_else

I did quite a bit of this in the transcoder, but never thought to check
elsewhere until I saw clippy::option_if_let_else. Sadly, its suggestion
is the unreadable Option::map_or_else rather than this simpler form.
That makes me disinclined to enable this across the board.

Author: featherbread

src/yaml/encoding.rs

@@ -365,10 +365,7 @@ where
 		self.pos += next.len() as u64;
 
 		let unit = self.endianness.decode_u32(next);
-		Some(match char::from_u32(unit) {
-			Some(ch) => Ok(ch),
-			None => Err(EncodingError::new(unit, pos).into()),
-		})
+		Some(char::from_u32(unit).ok_or_else(|| EncodingError::new(unit, pos).into()))
 	}
 }