atop install failure is confusing: Unable to find a match

[Sorin Sbarnea]

TASK [undercloud-setup : Install atop if configured so] fails and is ignored, causing confusions for people reading the logs.

It should either fail and stop the job execution or avoid errorness strigs like "FAILED!" or "Error: Unable to find a match" in the output (which are treated as errors).

TASK [undercloud-setup : Install atop if configured so] ************************ ************************
2019-03-10 15:11:38.839147 | primary | Sunday 10 March 2019 15:11:38 +0000 (0:00:00.197) 0:00:08.574 **********
2019-03-10 15:11:47.089238 | primary | fatal: [undercloud]: FAILED! => {
2019-03-10 15:11:47.089375 | primary | "changed": true,
2019-03-10 15:11:47.089684 | primary | "cmd": "source /etc/ci/mirror_info.sh\n atop_location=$(repoquery --repoid=osepel --repofrompath=osepel,$NODEPOOL_EPEL_MIRROR/7/x86_64/ --location atop)\n dnf install -y $atop_location",
2019-03-10 15:11:47.089760 | primary | "delta": "0:00:07.474556",
2019-03-10 15:11:47.089826 | primary | "end": "2019-03-10 15:11:47.030869",
2019-03-10 15:11:47.089859 | primary | "rc": 1,
2019-03-10 15:11:47.089935 | primary | "start": "2019-03-10 15:11:39.556313"
2019-03-10 15:11:47.089960 | primary | }
2019-03-10 15:11:47.089978 | primary |
2019-03-10 15:11:47.090003 | primary | STDOUT:
2019-03-10 15:11:47.090021 | primary |
2019-03-10 15:11:47.090126 | primary | Last metadata expiration check: 0:07:16 ago on Sun 10 Mar 2019 03:04:29 PM UTC.
2019-03-10 15:11:47.090232 | primary | atop-2.3.0-8.el7.x86_64.rpm 17 MB/s | 145 kB 00:00
2019-03-10 15:11:47.090282 | primary | No match for argument: osepel
2019-03-10 15:11:47.090327 | primary | No match for argument: 28
2019-03-10 15:11:47.090375 | primary | No match for argument: MB/s
2019-03-10 15:11:47.090418 | primary | No match for argument: |
2019-03-10 15:11:47.090463 | primary | No match for argument: 15
2019-03-10 15:11:47.090526 | primary | No match for argument: MB
2019-03-10 15:11:47.090591 | primary | No match for argument: 00:00
2019-03-10 15:11:47.090615 | primary |
2019-03-10 15:11:47.090633 | primary |
2019-03-10 15:11:47.090658 | primary | STDERR:
2019-03-10 15:11:47.090706 | primary |
2019-03-10 15:11:47.090832 | primary | Added osepel repo from http://mirror.regionone.rdo-cloud.rdoproject.org/epel/7/x86_64/
2019-03-10 15:11:47.090945 | primary | Last metadata expiration check: 0:00:04 ago on Sun 10 Mar 2019 03:11:40 PM UTC.
2019-03-10 15:11:47.090995 | primary | Error: Unable to find a match

Example https://logs.rdoproject.org/openstack-periodic/git.openstack.org/openstack-infra/tripleo-ci/master/periodic-tripleo-ci-fedora-28-standalone-master/af35f7c/job-output.txt.gz#_2019-03-10_15_11_47_089238