Client mode submit task client should keep same exitcode with AM

```
try

{ app.start(childArgs.toArray, sparkConf) }

catch

{ case t: Throwable => throw findCause(t) }

finally {
if (!isShell(args.primaryResource) && !isSqlShell(args.mainClass) &&
!isThriftServer(args.mainClass)) {
try

{ SparkContext.getActive.foreach(_.stop()) }

catch

{ case e: Throwable => logError(s"Failed to close SparkContext: $e") }

}
}
}
```