[SPARK-11110][BUILD] Remove transient annotation for parameters.

`transient` annotations on class parameters (not case class parameters or vals) causes compilation errors during compilation with Scala 2.11.
I understand that transient *parameters* make no sense, however I don't quite understand why the 2.10 compiler accepted them.

Note: in case it is preferred to keep the annotations in case someone would in the future want to redefine them as vals, it would also be possible to just add `val` after the annotation, e.g. `class Foo(transient x: Int)` becomes `class Foo(transient private val x: Int)`.

I chose to remove the annotation as it also reduces needles clutter, however please feel free to tell me if you prefer the second option and I'll update the PR

Author: Jakob Odersky <jodersky@gmail.com>

Closes apache#9126 from jodersky/sbt-scala-2.11.

core/src/main/scala/org/apache/spark/rpc/netty/NettyRpcEnv.scala

@@ -308,7 +308,7 @@ private[netty] class NettyRpcEnvFactory extends RpcEnvFactory with Logging {
   }
 }
 
-private[netty] class NettyRpcEndpointRef(@transient conf: SparkConf)
+private[netty] class NettyRpcEndpointRef(@transient private val conf: SparkConf)
   extends RpcEndpointRef(conf) with Serializable with Logging {
 
   @transient @volatile private var nettyEnv: NettyRpcEnv = _

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveContext.scala

@@ -89,9 +89,9 @@ private[hive] case class CurrentDatabase(ctx: HiveContext)
 class HiveContext private[hive](
     sc: SparkContext,
     cacheManager: CacheManager,
-    @transient listener: SQLListener,
-    @transient execHive: ClientWrapper,
-    @transient metaHive: ClientInterface,
+    listener: SQLListener,
+    @transient private val execHive: ClientWrapper,
+    @transient private val metaHive: ClientInterface,
     isRootContext: Boolean)
   extends SQLContext(sc, cacheManager, listener, isRootContext) with Logging {
   self =>