[SPARK-32172][CORE] Use createDirectory instead of mkdir

### What changes were proposed in this pull request?

Use Files.createDirectory() to create local directory instead of File.mkdir() in DiskBlockManager.
Many times, we will see such error log information like "Failed to create local dir in xxxxxx". But there is no clear information indicating why the directory creation failed.
When Files.createDirectory() fails to create a local directory, it can give specific error information for subsequent troubleshooting(also throws IOException).

### Why are the changes needed?

Throw clear error message when creating directory fails.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

`DiskBlockManagerSuite`

Closes apache#28997 from sidedoorleftroad/SPARK-32172.

Authored-by: sidedoorleftroad <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: sidedoorleftroad

core/src/main/scala/org/apache/spark/storage/DiskBlockManager.scala

@@ -18,6 +18,7 @@
 package org.apache.spark.storage
 
 import java.io.{File, IOException}
+import java.nio.file.Files
 import java.util.UUID
 
 import org.apache.spark.SparkConf
@@ -69,8 +70,8 @@ private[spark] class DiskBlockManager(conf: SparkConf, deleteFilesOnStop: Boolea
         old
       } else {
         val newDir = new File(localDirs(dirId), "%02x".format(subDirId))
-        if (!newDir.exists() && !newDir.mkdir()) {
-          throw new IOException(s"Failed to create local dir in $newDir.")
+        if (!newDir.exists()) {
+          Files.createDirectory(newDir.toPath)
         }
         subDirs(dirId)(subDirId) = newDir
         newDir