vmstat from proc-ps-4.0.x prints "Unable to create system stat structure"
if the /proc/cpuinfo output fails to contain topology info. While
Linux always prints topology info if the kernel has been built with
CONFIG_SMP, Cygwin only prints topology info if the CPU is known to
be multi-core (i. e., the HT feature flag is set).
Fix that by printing topology info all the time, even for single-core
CPUs.