[SPARK-19607][HOTFIX] Finding QueryExecution that matches provided executionId

Author: dongjoon-hyun

sql/core/src/test/scala/org/apache/spark/sql/execution/SQLExecutionSuite.scala

@@ -129,6 +129,8 @@ class SQLExecutionSuite extends SparkFunSuite {
     df.collect()
 
     assert(df.queryExecution === queryExecution)
+
+    spark.stop()
   }
 }