[KYUUBI #6370] For saveToFile, checking idx to prevent IndexOutOfBoun…

…dsException

# 🔍 Description
## Issue References 🔗

This pull request fixes #6370

## Describe Your Solution 🔧

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.

## Types of changes 🔖

- [ ] Bugfix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)

## Test Plan 🧪

#### Behavior Without This Pull Request ⚰️

#### Behavior With This Pull Request 🎉

#### Related Unit Tests

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# Checklist 📝

- [x] This patch was not authored or co-authored using [Generative Tooling](https://www.apache.org/legal/generative-tooling.html)

**Be nice. Be informative.**

Closes #6372 from turboFei/kyuubi_6370.

Closes #6370

d0c6a92 [Wang, Fei] fix

Authored-by: Wang, Fei <[email protected]>
Signed-off-by: Wang, Fei <[email protected]>

externals/kyuubi-spark-sql-engine/src/main/scala/org/apache/kyuubi/engine/spark/operation/FetchOrcStatement.scala

@@ -79,6 +79,7 @@ class OrcFileIterator(fileList: ListBuffer[LocatedFileStatus]) extends Iterator[
   var idx = 0
 
   override def hasNext: Boolean = {
+    if (idx >= iters.size) return false
     val hasNext = iters(idx).hasNext
     if (!hasNext) {
       iters(idx).close()