[SPARK-19891][SS] Await Batch Lock notified on stream execution exit

## What changes were proposed in this pull request?

We need to notify the await batch lock when the stream exits early e.g., when an exception has been thrown.

## How was this patch tested?

Current tests that throw exceptions at runtime will finish faster as a result of this update.

zsxwing

Please review http://spark.apache.org/contributing.html

 before opening a pull request.

Author: Tyson Condie <tcondie@gmail.com>

Closes #17231 from tcondie/kafka-writer.

(cherry picked from commit 501b7111)
Signed-off-by: Shixiong Zhu <shixiong@databricks.com>