Description of problem:
When uninstalling, the script tries to remove an existing sadc container.  That works fine, unless no container was started, or it was already removed (manually).  In that case, the script returns non-zero exit status when it shouldn't (since removing the container was the goal).

Version-Release number of selected component (if applicable):

registry.access.redhat.com/rhel7/sadc         latest              96ca6a153fd6        16 hours ago        215 MB

How reproducible:
Trivial

Steps to Reproduce:
1. atomic install registry.access.redhat.com/rhel7/sadc:latest
2. atomic uninstall registry.access.stage.redhat.com/rhel7/sadc:latest

Actual results:
-bash-4.2# atomic uninstall registry.access.stage.redhat.com/rhel7/sadc:latest
docker run --rm --privileged -v /:/host -e HOST=/host -v /var/log:/var/log -e IMAGE=registry.access.stage.redhat.com/rhel7/sadc:latest -e NAME=sadc registry.access.stage.redhat.com/rhel7/sadc:latest /usr/local/bin/sysstat-uninstall.sh ; docker rm -f sadc
Error response from daemon: no such id: sadc
Error: failed to remove containers: [sadc]
-bash-4.2# echo $?
1

Expected results:
-bash-4.2# atomic uninstall registry.access.stage.redhat.com/rhel7/sadc:latest
docker run --rm --privileged -v /:/host -e HOST=/host -v /var/log:/var/log -e ...whatever...
-bash-4.2# echo $?
0


Additional info:
The rsyslog image uninstall does not have this problem