[SPARK-2767] [SQL] SparkSQL CLI doens't output error message if query failed.

(Actually I'd like to add the comment to the `catch` clause of this `try` block, but GitHub doesn't allow me to.)

One annoying issue here is that the exception throw is only recorded to the logger, not reported to the console. Thus, when using `bin/spark-sql`, users can only see the following unintuitive exception:

```
$ ./bin/spark-sql
spark-sql> foo;
NoViableAltException(26@[])
        at org.apache.hadoop.hive.ql.parse.HiveParser.statement(HiveParser.java:902)
        at org.apache.hadoop.hive.ql.parse.ParseDriver.parse(ParseDriver.java:190)
        at org.apache.hadoop.hive.ql.parse.ParseDriver.parse(ParseDriver.java:161)
        ...
```

Unless they run `spark-sql --hiveconf hive.root.logger=INFO,console` (similar to `shark-withinfo` in Shark):

```
$ ./bin/spark-sql --hiveconf hive.root.logger=INFO,console
spark-sql> foo;
spark-sql> foo;
14/08/01 11:17:03 INFO parse.ParseDriver: Parsing command: foo
NoViableAltException(26@[])
        at org.apache.hadoop.hive.ql.parse.HiveParser.statement(HiveParser.java:902)
        at org.apache.hadoop.hive.ql.parse.ParseDriver.parse(ParseDriver.java:190)
        at org.apache.hadoop.hive.ql.parse.ParseDriver.parse(ParseDriver.java:161)
        ...
14/08/01 11:17:04 ERROR thriftserver.SparkSQLDriver: Failed in [foo]
org.apache.spark.sql.hive.HiveQl$ParseException: Failed to parse: foo
        at org.apache.spark.sql.hive.HiveQl$.parseSql(HiveQl.scala:214)
        at org.apache.spark.sql.hive.HiveContext.hiveql(HiveContext.scala:76)
        at org.apache.spark.sql.hive.HiveContext.hql(HiveContext.scala:79)
        ...
```

To fix this, we can print the exception (if any) to console after checking response code of the `CommandProcessorResponse` object in [`SparkSQLCLIDriver`](https://github.com/apache/spark/blob/8f51491ea78d8e88fc664c2eac3b4ac14226d98f/sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLCLIDriver.scala#L291).