Add SqlNewHadoopRDD.unsetInputFileName() that I accidentally deleted.

Author: JoshRosen

core/src/main/scala/org/apache/spark/rdd/SqlNewHadoopRDD.scala

@@ -190,6 +190,7 @@ private[spark] class SqlNewHadoopRDD[V: ClassTag](
 
       private def close() {
         if (reader != null) {
+          SqlNewHadoopRDD.unsetInputFileName()
           // Close the reader and release it. Note: it's very important that we don't close the
           // reader more than once, since that exposes us to MAPREDUCE-5918 when running against
           // Hadoop 1.x and older Hadoop 2.x releases. That bug can lead to non-deterministic