[CPUFREQ] Fix use after free of struct powernow_k8_data
Easy fix for a regression introduced in 2.6.31.
On managed CPUs the cpufreq.c core will call driver->exit(cpu) on the
managed cpus and powernow_k8 will free the core's data.
Later driver->get(cpu) function might get called trying to read out the
current freq of a managed cpu and the NULL pointer check does not work on
the freed object -> better set it to NULL.
->get() is unsigned and must return 0 as invalid frequency.
Signed-off-by: Thomas Renninger <trenn@suse.de> Tested-by: Michal Schmidt <mschmidt@redhat.com> CC: stable@kernel.org Signed-off-by: Dave Jones <davej@redhat.com>