Sometimes the error does not tell much, so as `exit status 1` and
printing the output along returning the error is useful.
For instance, I saw a job failing with no osd and the prepare job had
those lines:
```
exec: Running command: lsblk /dev/sdb1 --bytes --nodeps --pairs ....
inventory: skipping device "sdb1". exit status 1
```
We need to understand more about the lsblk issue.
Signed-off-by: Sébastien Han <seb@redhat.com>
Sébastien Han
b7f55362b2