IMPALA-1038: Abort test run if any test fails

This behavior regressed recently, this fixes the regression.

Change-Id: I80939131953fc1838da0690c3e7e7bf455bd6180
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2968
Reviewed-by: Ippokratis Pandis <ipandis@cloudera.com>
Tested-by: jenkins