Fix missing return statement when writing "off" to intel_pstate status
sysfs I/F.
Fixes: 381d927428aa ("cpufreq: intel_pstate: Free memory only when turning off") Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>