[SPARK-2742][yarn] delete useless variables

Author: XuTingjun <1039320815@qq.com>

Closes #1614 from XuTingjun/yarn-bug and squashes the following commits:

f07096e [XuTingjun] Update ClientArguments.scala

yarn/common/src/main/scala/org/apache/spark/deploy/yarn/ClientArguments.scala

@@ -39,7 +39,6 @@ class ClientArguments(val args: Array[String], val sparkConf: SparkConf) {
   var amMemory: Int = 512 // MB
   var amClass: String = "org.apache.spark.deploy.yarn.ApplicationMaster"
   var appName: String = "Spark"
-  var inputFormatInfo: List[InputFormatInfo] = null
   var priority = 0
 
   parseArgs(args.toList)
@@ -58,8 +57,7 @@ class ClientArguments(val args: Array[String], val sparkConf: SparkConf) {
 
   private def parseArgs(inputArgs: List[String]): Unit = {
     val userArgsBuffer: ArrayBuffer[String] = new ArrayBuffer[String]()
-    val inputFormatMap: HashMap[String, InputFormatInfo] = new HashMap[String, InputFormatInfo]()
-
+  
     var args = inputArgs
 
     while (!args.isEmpty) {
@@ -145,7 +143,6 @@ class ClientArguments(val args: Array[String], val sparkConf: SparkConf) {
     }
 
     userArgs = userArgsBuffer.readOnly
-    inputFormatInfo = inputFormatMap.values.toList
   }