sudo is broken for initscripts when requiretty is set (as is default)

1. You should never have to use su or sudo in an init script to do things as root -- init scripts are meant to be run **as** root
1. sudo may not be present on the instance, and your package doesn't include it as a requirement
1. switching user to run as pdagent can be achieved via `su` which is always present on the base image
1. `sudo` breaks when `requiretty` is set -- as is the default in CentOS 6.5, Amazon Linux AMI, etc. etc. -- this means that starting pdagent via `cfn-init`, for example, will break.