For cpuid leaf 0xb the bits 8-15 in ECX register define the end of counting
leaf.      The previous code was using bits 0-7 for this purpose, which is
a bug.
Signed-off-by: NNitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>