Fix the scala style errors of OpenMLDB Spark

Now we have some scala style error in project https://github.com/4paradigm/spark .

The issue points to scala style errors in the OpenMLDB Spark project. First, locate the project at https://github.com/4paradigm/spark and run a Scala style checker (like scalafmt or scalastyle) to identify the errors. Then, fix the formatting issues in the relevant Scala files. Verify the fixes by running the style checker again and ensuring the build passes.

索引モデルが issue の本文から書いたものです。