SPARK-1607. HOTFIX: Fix syntax adapting Int result to Short

Sorry folks. This should make the change for SPARK-1607 compile again. Verified this time with the yarn build enabled.

Author: Sean Owen <sowen@cloudera.com>

Closes #556 from srowen/SPARK-1607.2 and squashes the following commits:

e3fe7a3 [Sean Owen] Fix syntax adapting Int result to Short

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

@@ -60,10 +60,10 @@ trait ClientBase extends Logging {
 
   // Staging directory is private! -> rwx--------
   val STAGING_DIR_PERMISSION: FsPermission =
-    FsPermission.createImmutable(Integer.parseInt("700", 8): Short)
+    FsPermission.createImmutable(Integer.parseInt("700", 8).toShort)
   // App files are world-wide readable and owner writable -> rw-r--r--
   val APP_FILE_PERMISSION: FsPermission =
-    FsPermission.createImmutable(Integer.parseInt("644", 8): Short)
+    FsPermission.createImmutable(Integer.parseInt("644", 8).toShort)
 
   // TODO(harvey): This could just go in ClientArguments.
   def validateArgs() = {