Description
"Use --prompt or --force to override" should not in the warning for virt-image since neither prompt nor force option are availabe for virt-image.

Version:
# rpm -qa libvirt python-virtinst
python-virtinst-0.600.0-18.el6.noarch
libvirt-0.10.2-26.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1. create virtual machines by virt-image with vcpus exceeding physical CPU and check-cpu option.
# virt-image image.xml --vcpus=9  --check-cpu --debug
Mon, 23 Sep 2013 05:16:06 DEBUG    Launched with command line:
/usr/bin/virt-image image.xml --vcpus=9 --check-cpu --debug
Mon, 23 Sep 2013 05:16:06 DEBUG    Requesting libvirt URI default
Mon, 23 Sep 2013 05:16:06 DEBUG    Received libvirt URI qemu:///system
Mon, 23 Sep 2013 05:16:06 ERROR    You have asked for more virtual CPUs (9) than there are physical CPUs (8) on the host. This will work, but performance will be poor.  (Use --prompt or --force to override)

Actual results：
Mon, 23 Sep 2013 05:16:06 ERROR    You have asked for more virtual CPUs (9) than there are physical CPUs (8) on the host. This will work, but performance will be poor.  (Use --prompt or --force to override)

Expected results:
"Use --prompt or --force to override" should not in the warning for virt-image since there's nerther prompt nor force option for virt-image.