[SPARK-4295][External]Fix exception in SparkSinkSuite

Handle exception in SparkSinkSuite, please refer to [SPARK-4295]

Author: maji2014 <maji3@asiainfo.com>

Closes #3177 from maji2014/spark-4295 and squashes the following commits:

312620a [maji2014] change a new statement for spark-4295
24c3d21 [maji2014] add log4j.properties for SparkSinkSuite and spark-4295
c807bf6 [maji2014] Fix exception in SparkSinkSuite

external/flume-sink/src/test/resources/log4j.properties

+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Set everything to be logged to the file streaming/target/unit-tests.log
+log4j.rootCategory=INFO, file
+# log4j.appender.file=org.apache.log4j.FileAppender
+log4j.appender.file=org.apache.log4j.FileAppender
+log4j.appender.file.append=false
+log4j.appender.file.file=target/unit-tests.log
+log4j.appender.file.layout=org.apache.log4j.PatternLayout
+log4j.appender.file.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss.SSS} %t %p %c{1}: %m%n
+
+# Ignore messages below warning level from Jetty, because it's a bit verbose
+log4j.logger.org.eclipse.jetty=WARN
+

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(scala.util.Random.nextString(10))
     channel.configure(channelContext)
 
     val sink = new SparkSink()