[libvirt] Fix wrong nodeinfo->mhz when cpufreq is enabled

Hi, I've written a little patch to fix wrong nodeinfo->mhz when the Linux kernel module cpufreq and a typical governor like ondemand are loaded. nodeinfo->mhz is then too low as libvirt just reads /proc/cpuinfo, entry "cpu MHz". This patch reads /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq if existing and corrects nodeinfo->mhz if the value found is higher. Using cpu0 is a crude hack but as discussed on IRC, considering different governors/maximum frequencies per cpu/core would require changing the nodeinfo struct, which would break the API. Some more info: https://bugzilla.redhat.com/show_bug.cgi?id=559762 Please have a careful look at my patch, my last C is quite some time ago. I tried to stick to linuxNodeInfoCPUPopulate, but f.e., checking for "&& *p == '\0'" after virStrToLong_ui doesn't work and I'm wondering why scaling_max_freq may not be terminated with by NUL? I also hope the file handling is correct, but please have a look. There is still some todo: Some logging would be helpful, maybe one of you could point out which function best to use? This is my first patch, so hopefully it follows in the next mail ;-) kr, tom