PM / QoS: Fix writing 'auto' to pm_qos_latency_tolerance_us

If it was already 'auto', then writing 'auto' again would
incorrectly fail.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 file changed