Fix exception in SparkSinkSuite

Author: maji2014

external/flume-sink/src/test/scala/org/apache/spark/streaming/flume/sink/SparkSinkSuite.scala

@@ -159,6 +159,7 @@ class SparkSinkSuite extends FunSuite {
     channelContext.put("transactionCapacity", 1000.toString)
     channelContext.put("keep-alive", 0.toString)
     channelContext.putAll(overrides)
+    channel.setName(getClass.getDeclaredMethods.toString)
     channel.configure(channelContext)
 
     val sink = new SparkSink()