We have a race condition where podman build can fail
but still return an exit code of 0. This PR ensures
that as soon as the build fails, the failed flag is set
eliminating the race.
Fixes: https://github.com/containers/podman/issues/10029
[NO TESTS NEEDED] Tests of failed builds are already in place, and
the elimination of the race should be enough.
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>