Don't check serializability of DStream transforms.

Since the DStream is reachable from within these closures, they aren't
checkable by the straightforward technique of passing them to the
closure serializer.

streaming/src/main/scala/org/apache/spark/streaming/dstream/DStream.scala

@@ -533,15 +533,15 @@ abstract class DStream[T: ClassTag] (
    * on each RDD of 'this' DStream.
    */
   def transform[U: ClassTag](transformFunc: RDD[T] => RDD[U]): DStream[U] = {
-    transform((r: RDD[T], t: Time) => context.sparkContext.clean(transformFunc(r)))
+    transform((r: RDD[T], t: Time) => context.sparkContext.clean(transformFunc(r), false))
   }
 
   /**
    * Return a new DStream in which each RDD is generated by applying a function
    * on each RDD of 'this' DStream.
    */
   def transform[U: ClassTag](transformFunc: (RDD[T], Time) => RDD[U]): DStream[U] = {
-    val cleanedF = context.sparkContext.clean(transformFunc)
+    val cleanedF = context.sparkContext.clean(transformFunc, false)
     val realTransformFunc =  (rdds: Seq[RDD[_]], time: Time) => {
       assert(rdds.length == 1)
       cleanedF(rdds.head.asInstanceOf[RDD[T]], time)
@@ -556,7 +556,7 @@ abstract class DStream[T: ClassTag] (
   def transformWith[U: ClassTag, V: ClassTag](
       other: DStream[U], transformFunc: (RDD[T], RDD[U]) => RDD[V]
     ): DStream[V] = {
-    val cleanedF = ssc.sparkContext.clean(transformFunc)
+    val cleanedF = ssc.sparkContext.clean(transformFunc, false)
     transformWith(other, (rdd1: RDD[T], rdd2: RDD[U], time: Time) => cleanedF(rdd1, rdd2))
   }
 
@@ -567,7 +567,7 @@ abstract class DStream[T: ClassTag] (
   def transformWith[U: ClassTag, V: ClassTag](
       other: DStream[U], transformFunc: (RDD[T], RDD[U], Time) => RDD[V]
     ): DStream[V] = {
-    val cleanedF = ssc.sparkContext.clean(transformFunc)
+    val cleanedF = ssc.sparkContext.clean(transformFunc, false)
     val realTransformFunc = (rdds: Seq[RDD[_]], time: Time) => {
       assert(rdds.length == 2)
       val rdd1 = rdds(0).asInstanceOf[RDD[T]]