[SPARK-7419][Streaming][Tests]Fix CheckpointSuite.recovery with file input stream

[zsxwing]

Fix this failure: https://amplab.cs.berkeley.edu/jenkins/job/Spark-Master-SBT/2886/AMPLAB_JENKINS_BUILD_PROFILE=hadoop2.3,label=centos/testReport/junit/org.apache.spark.streaming/CheckpointSuite/recovery_with_file_input_stream/

To reproduce this failure, you can add Thread.sleep(2000) before this line

spark/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala

Line 477 in a9c4e29

for ((i, index) <- Seq(7, 8, 9).zipWithIndex) {

[zsxwing]

This line will add one batch, so I move it here. And because of this line, the clock of the recovery StreamingContext will be 14000ms.

[SparkQA]

Test build #36930 has finished for PR 7323 at commit b3caf58.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[zsxwing]

This is not necessary now.

[andrewor14]

I've manually triggered this test a few more times.

[SparkQA]

Test build #1023 has finished for PR 7323 at commit b3caf58.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #1021 has finished for PR 7323 at commit b3caf58.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #1020 has finished for PR 7323 at commit b3caf58.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #1022 has finished for PR 7323 at commit b3caf58.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[andrewor14]

Looks great. Merging into master and 1.4. Thanks Ryan!!