remove outdated runtime Information scala home

Author: witgo <witgo@qq.com>

Closes #728 from witgo/scala_home and squashes the following commits:

cdfd8be [witgo] Merge branch 'master' of https://github.com/apache/spark into scala_home
fac094a [witgo] remove outdated runtime Information scala home

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

@@ -281,8 +281,7 @@ object SparkEnv extends Logging {
     val jvmInformation = Seq(
       ("Java Version", "%s (%s)".format(Properties.javaVersion, Properties.javaVendor)),
       ("Java Home", Properties.javaHome),
-      ("Scala Version", Properties.versionString),
-      ("Scala Home", Properties.scalaHome)
+      ("Scala Version", Properties.versionString)
     ).sorted
 
     // Spark properties