qemu: properly quit migration with abort_on_error
    
    When EIO comes to qemu while it's replying to
    qemuMigrationUpdateJobStatus(), qemu blocks, the migration of RAM can
    complete in the meantime, and when qemu unblocks, it sends us
    BLOCK_IO_ERROR plus migrations "status": "complete".  Even though we
    act upon the BLOCK_IO_ERROR by setting the proper state of the domain,
    the call still waits for the proper reply on monitor for query_migrate
    and after it gets it, it checks that migration is completed and the
    migration is finished.  This is what abort_on_error flag was meant for
    (we can migrate with these errors, but this flag must inhibit such
    behaviour).  Changing the order of the steps guarantees the flag works
    properly.
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1045833
    
    Signed-off-by: Martin Kletzander <mkletzan@redhat.com>