Fix sasl thirdparty build to work on all distros.

Our packaging jobs use ~ in the path containing IMPALA_HOME. Getting
sasl's 'make install' to work with ~ doesn't seem possible. Let's just
install it somewhere else.

Change-Id: Ie59a5a35609e7bff56e5684d34411b46f8ddcc0c
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4304
Reviewed-by: Henry Robinson <henry@cloudera.com>
Tested-by: jenkins