I know it's been a long time since this question was asked, but I think I found an easier way.
If I understood correctly, you want to check the result of the build - if it was a success or a failure, in other words.
Jenkins CLI's "build" command changes the exit code depending on the result of the build, as long as you use the -s or -f option at the end.
java -jar jenkins-cli.jar -s <url of Jenkins instance> build <project> -s
java -jar jenkins-cli.jar -s <url of Jenkins instance> build <project> -f
Notice that the option goes at the end; it's not the first -s, which is used to define the url of the jenkins instance.
And then, to get the result, you can use $?
If the result is 0, it was a success. If it's something other than 0, it was a failure.
Reference: I can't find a public Jenkins instance that gives access to this page, but it can be found in your local Jenkins instance:
http://<url of Jenkins Instance>/cli/command/build. It also explains the difference between -s and -f.