iscsi: avoid failing if just one path is down
iscsi: avoid failing if just one path is down

Avoid failing if configured for iscsi multipath
and just one of the path there is down.
Use a different connection uuid on each path
to be able to correlate failures with paths.

Change-Id: I414f100fb641d1512d9af320332221495d79817b
Bug-Url: https://bugzilla.redhat.com/1543424
Signed-off-by: Simone Tiraboschi <cb03129c66ba4da7ba7044049d0f43907bf857bb@redhat.com>

oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha