qemu: blockjob: Add flag for invalid block job data

The job data saved in the XML may be partially invalid e.g. if something
is missing. To prevent losing a domain with such a job add a flag to the
job data so that job APIs can ignore such a job and we can just cancel
it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_blockjob.h

@@ -80,6 +80,8 @@ struct _qemuBlockJobData {
     bool synchronous; /* API call is waiting for this job */
 
     int newstate; /* qemuBlockjobState, subset of events emitted by qemu */
+
+    bool invalidData; /* the job data (except name) is not valid */
 };
 
 int