Not having OPP defined for a device is not a crime, we should not splat
warning in this case. Also, it seems that we are ready to accept invalid
dev (find_device_opp will return ERR_PTR(-EINVAL) then) so let's not
crash in dev_name() in such case.
Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>