[SPARK-27202][MINOR][SQL] Update comments to keep according with code

## What changes were proposed in this pull request?

Update comments in `InMemoryFileIndex.listLeafFiles` to keep according with code.

## How was this patch tested?

existing test cases

Closes apache#24146 from WangGuangxin/SPARK-27202.

Authored-by: wangguangxin.cn <[email protected]>
Signed-off-by: Sean Owen <[email protected]>

Author: WangGuangxin

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

@@ -308,7 +308,7 @@ object InMemoryFileIndex extends Logging {
       //   implementations don't actually issue RPC for this method.
       //
       // - Here we are calling `getFileBlockLocations` in a sequential manner, but it should not
-      //   be a big deal since we always use to `listLeafFilesInParallel` when the number of
+      //   be a big deal since we always use to `bulkListLeafFiles` when the number of
       //   paths exceeds threshold.
       case f =>
         // The other constructor of LocatedFileStatus will call FileStatus.getPermission(),

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

@@ -89,7 +89,7 @@ abstract class PartitioningAwareFileIndex(
     if (partitionSpec().partitionColumns.isEmpty) {
       // For each of the root input paths, get the list of files inside them
       rootPaths.flatMap { path =>
-        // Make the path qualified (consistent with listLeafFiles and listLeafFilesInParallel).
+        // Make the path qualified (consistent with listLeafFiles and bulkListLeafFiles).
         val fs = path.getFileSystem(hadoopConf)
         val qualifiedPathPre = fs.makeQualified(path)
         val qualifiedPath: Path = if (qualifiedPathPre.isRoot && !qualifiedPathPre.isAbsolute) {
@@ -203,7 +203,7 @@ abstract class PartitioningAwareFileIndex(
 
       case None =>
         rootPaths.map { path =>
-          // Make the path qualified (consistent with listLeafFiles and listLeafFilesInParallel).
+          // Make the path qualified (consistent with listLeafFiles and bulkListLeafFiles).
           val qualifiedPath = path.getFileSystem(hadoopConf).makeQualified(path)
           if (leafFiles.contains(qualifiedPath)) qualifiedPath.getParent else qualifiedPath }.toSet
     }