One more dead code :)

Author: liancheng

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetFilters.scala

@@ -29,8 +29,6 @@ import org.apache.spark.sql.sources
 import org.apache.spark.sql.types._
 
 private[sql] object ParquetFilters {
-  val PARQUET_FILTER_DATA = "org.apache.spark.sql.parquet.row.filter"
-
   case class SetInFilter[T <: Comparable[T]](
     valueSet: Set[T]) extends UserDefinedPredicate[T] with Serializable {