[ 1963584 ] fix build.xml cobertura test harness

git-svn-id: https://svn.apache.org/repos/asf/hadoop/zookeeper/trunk@670968 13f79535-47bb-0310-9956-ffa450edef68

zookeeper/build.xml

@@ -415,6 +415,7 @@
                 <fileset dir="${test.src.dir}" includes="**/${testcase}.java"/>
             </batchtest>
         </junit>
+        <fail if="tests.failed">Tests failed!</fail>
     </target>
 
     <target name="cobertura-report" depends="cobertura-test">