qemu: Create completed jobData in qemuMigrationSrcComplete

qemu: Create completed jobData in qemuMigrationSrcComplete

Normally the structure is created once the source reports completed
migration, but with post-copy migration we can get here even after
libvirt daemon was restarted. It doesn't make sense to preserve the
structure in our status XML as we're going to rewrite almost all of it
while refreshing the stats anyway. So we just create the structure here
if it doesn't exist to make sure we can properly report statistics of a
completed migration.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>