Log BLOCK_JOB_COMPLETED error

[dupondje]

The BLOCK_JOB_COMPLETED event contains some additional info and and error message when something failed.
It would be useful to include the error message somewhere in vdsm/ovirt.

Line from libvirt logs:

4114448: info : qemuMonitorJSONIOProcessLine:205 : QEMU_MONITOR_RECV_EVENT: mon=0x7f1a9c0082f0 event={"timestamp": {"seconds": 1688026018, "microseconds": 64056}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "commit-sdb-libvirt-2-format", "len": 73747988480, "offset": 7143424, "speed": 0, "type": "commit", 
"error": "No space left on device"}}

[nirs]

@dupondje If this info is passed to vdsm in the event, vdsm can log it. You can check how vdsm handles the event and if we have more info in the event here:

vdsm/lib/vdsm/clientIF.py

Line 647 in 126bb0d

def dispatchLibvirtEvents(self, conn, dom, *args):