[SPARK-25521][SQL] Job id showing null in the logs when insert into command Job is finished.

## What changes were proposed in this pull request?
``As part of  insert command  in FileFormatWriter, a job context is created for handling the write operation , While initializing the job context using setupJob() API
in HadoopMapReduceCommitProtocol , we set the jobid  in the Jobcontext configuration.In FileFormatWriter since we are directly getting the jobId from the map reduce JobContext the job id will come as null  while adding the log. As a solution we shall get the jobID from the configuration of the map reduce Jobcontext.``

## How was this patch tested?
Manually, verified the logs after the changes.

![spark-25521 1](https://user-images.githubusercontent.com/12999161/46164933-e95ab700-c2ac-11e8-88e9-49fa5100b872.PNG)

Closes apache#22572 from sujith71955/master_log_issue.

Authored-by: s71955 <[email protected]>
Signed-off-by: Wenchen Fan <[email protected]>

Author: sujith71955

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/FileFormatWriter.scala

@@ -183,15 +183,15 @@ object FileFormatWriter extends Logging {
       val commitMsgs = ret.map(_.commitMsg)
 
       committer.commitJob(job, commitMsgs)
-      logInfo(s"Job ${job.getJobID} committed.")
+      logInfo(s"Write Job ${description.uuid} committed.")
 
       processStats(description.statsTrackers, ret.map(_.summary.stats))
-      logInfo(s"Finished processing stats for job ${job.getJobID}.")
+      logInfo(s"Finished processing stats for write job ${description.uuid}.")
 
       // return a set of all the partition paths that were updated during this job
       ret.map(_.summary.updatedPartitions).reduceOption(_ ++ _).getOrElse(Set.empty)
     } catch { case cause: Throwable =>
-      logError(s"Aborting job ${job.getJobID}.", cause)
+      logError(s"Aborting job ${description.uuid}.", cause)
       committer.abortJob(job)
       throw new SparkException("Job aborted.", cause)
     }