Description of problem:
Installing qemu=system-x86 triggers a warning on non-KVM capable systems.

Version-Release number of selected component (if applicable):
1.0-15

How reproducible:
install qemu-sysem-x86 (eg, via yum update)

Steps to Reproduce:
1. yum update qemu-system-x86
2.
3.
  
Actual results:
Non-fatal POSTIN scriptlet failure in rpm package 2:qemu-system-x86-1.0-15.fc18.i686
warning: %post(qemu-system-x86-2:1.0-15.fc18.i686) scriptlet failed, exit status 1

Expected results:
NOTA

Additional info:
0) $ rpm -q qemu-system-x86 --scripts
postinstall scriptlet (using /bin/sh):
# load kvm modules now, so we can make sure no reboot is needed.
# If there's already a kvm module installed, we don't mess with it
sh /etc/sysconfig/modules/kvm.modules

1) $ rpm -qf /etc/sysconfig/modules/kvm.modules 
qemu-system-x86-1.0-15.fc18.i686

2) $ cat /etc/sysconfig/modules/kvm.modules 
#!/bin/sh

case "$(</proc/cpuinfo)" in
    *vmx*) vmx=1 ;;
    *svm*) svm=1 ;;
esac

[ "$vmx" ] && modprobe -b kvm-intel >/dev/null 2>&1
[ "$svm" ] && modprobe -b kvm-amd >/dev/null 2>&1
[ "$vmx" -o "$svm" ] && modprobe -b vhost-net >/dev/null 2>&1

3) That kvm.modules script apparently needs to exit early (with a zero exit status) if both "$vmx" and "$svm" are empty.