SPARK-1330 removed extra echo from comput_classpath.sh

remove the extra echo which prevents spark-class from working.  Note that I did not update the comment above it, which is also wrong because I'm not sure what it should do.

Should hive only be included if explicitly built with sbt hive/assembly or should sbt assembly build it?

Author: Thomas Graves <tgraves@apache.org>

Closes #241 from tgravescs/SPARK-1330 and squashes the following commits:

b10d708 [Thomas Graves] SPARK-1330 removed extra echo from comput_classpath.sh