fix error getting CPUInfo on darwin.
fix error getting CPUInfo on darwin.

choplin/gopsutil,neezgee/gopsutil,xiaoyanit/gopsutil,jmptrader/gopsutil,yyljlyy/gopsutil,andyjones/gopsutil,influxdb/gopsutil,choplin/gopsutil,chendrak/gopsutil,vrecan/gopsutil,desp0916/gopsutil,yyljlyy/gopsutil,chendrak/gopsutil,xiaoyanit/gopsutil,mayowa/gopsutil,oliveagle/gopsutil,monicasarbu/gopsutil,oliveagle/gopsutil,jmptrader/gopsutil,desp0916/gopsutil,lonemage/gopsutil,neezgee/gopsutil,andyjones/gopsutil,mayowa/gopsutil,lonemage/gopsutil,vrecan/gopsutil,influxdb/gopsutil,monicasarbu/gopsutil