Update rust/src/checkpoints.rs

Co-authored-by: Christian Williams <christianwilliams79@gmail.com>

rust/src/checkpoints.rs

@@ -400,7 +400,7 @@ fn parquet_bytes_from_state(state: &DeltaTableState) -> Result<Vec<u8>, Checkpoi
 
     debug!("Writing to checkpoint parquet buffer...");
     // Write the Checkpoint parquet file.
-    let writeable_cursor = Cursor::new(vec![]);
+    let mut writeable_cursor = Cursor::new(vec![]);
     let mut writer = ArrowWriter::try_new(&mut writeable_cursor, arrow_schema.clone(), None)?;
     let options = DecoderOptions::new().with_batch_size(CHECKPOINT_RECORD_BATCH_SIZE);
     let decoder = Decoder::new(arrow_schema, options);