Add a space after comma.
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Message-Id: <1427374663-10168-1-git-send-email-arei.gonglei@huawei.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>