Move a bracket in validateSettings of SparkConf

Move a bracket in validateSettings of SparkConf

Author: hzw19900416 <carlmartinmax@gmail.com>

Closes #2012 from hzw19900416/codereading and squashes the following commits:

e717fb6 [hzw19900416] Move a bracket in validateSettings of SparkConf

core/src/main/scala/org/apache/spark/SparkConf.scala

@@ -227,7 +227,7 @@ class SparkConf(loadDefaults: Boolean) extends Cloneable with Logging {
     // Validate spark.executor.extraJavaOptions
     settings.get(executorOptsKey).map { javaOpts =>
       if (javaOpts.contains("-Dspark")) {
-        val msg = s"$executorOptsKey is not allowed to set Spark options (was '$javaOpts)'. " +
+        val msg = s"$executorOptsKey is not allowed to set Spark options (was '$javaOpts'). " +
           "Set them directly on a SparkConf or in a properties file when using ./bin/spark-submit."
         throw new Exception(msg)
       }