The commit efab27afbf02743a3a2582e9a111eb1b7d985b26 in libvirt uses
/dev/%s for logical pools, change the tests to accommodate it.
(crobinso: additional fix to work with older libvirt)
After commit 590c8dbebf, the tests got
broken due to the fact that the commit broke something that was
working. I'm changing the error to warning and fixing the tests.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>