Fix scalastyle and address review comment

Author: szehon-ho

sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala

@@ -1538,7 +1538,7 @@ object SQLConf {
       .createWithDefault(false)
 
   val V2_BUCKETING_ALLOW_COMPATIBLE_TRANSFORMS =
-    buildConf("spark.sql.sources.v2.bucketing.allow.enabled")
+    buildConf("spark.sql.sources.v2.bucketing.allowCompatibleTransforms.enabled")
       .doc("Whether to allow storage-partition join in the case where the partition transforms" +
         "are compatible but not identical.  This config requires both " +
         s"${V2_BUCKETING_ENABLED.key} and ${V2_BUCKETING_PUSH_PART_VALUES_ENABLED.key} to be " +

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/BatchScanExec.scala

@@ -237,6 +237,7 @@ case class BatchScanExec(
 
         case _ => filteredPartitions
       }
+
       new DataSourceRDD(
         sparkContext, finalPartitions, readerFactory, supportsColumnar, customMetrics)
     }

sql/core/src/test/scala/org/apache/spark/sql/connector/KeyGroupedPartitioningSuite.scala

@@ -1549,7 +1549,7 @@ class KeyGroupedPartitioningSuite extends DistributionAndOrderingSuiteBase {
             Row(3, 4, 2, 2, "ad", "04"),
             Row(4, 3, 3, 3, "ae", "05"),
             Row(5, 2, 4, 4, "af", "06"),
-            Row(6, 1, 5, 5, "ag", "07"),
+            Row(6, 1, 5, 5, "ag", "07")
           ))
         }
       }

sql/core/src/test/scala/org/apache/spark/sql/connector/catalog/functions/transformFunctions.scala

@@ -91,7 +91,7 @@ object BucketFunction extends ReducibleFunction[Int, Int] {
                        otherNumBuckets: Option[_]): Option[Reducer[Int]] = {
     (thisNumBuckets, otherNumBuckets) match {
       case (Some(thisNumBucketsVal: Int), Some(otherNumBucketsVal: Int))
-        if func.isInstanceOf[ReducibleFunction[_, _]] &&
+        if func == BucketFunction &&
           ((thisNumBucketsVal > otherNumBucketsVal) &&
             (thisNumBucketsVal % otherNumBucketsVal == 0)) =>
         Some(BucketReducer(thisNumBucketsVal, otherNumBucketsVal))