maven,scriptlet,mojo,rpm-maven-plugin
As pointed out in the bug, the directoryIncluded[1] mapping controls this behavior. If you set this to false you will get the behavior you desire. [1] - http://mojo.codehaus.org/rpm-maven-plugin/map-params.html#directoryIncluded...
git,maven,buildnumber-maven-plugin,rpm-maven-plugin
Thanks to @musiKk 's suggestion, I used git-commit-id-plugin. I had several problems at first because I didn't configure it properly. Though the plugin is not mature enough, it's getting the job done.