thermal: core: Drop redundant check from thermal_zone_device_update()

Since __thermal_zone_device_update() checks if tz->state is
TZ_STATE_READY and bails out immediately otherwise, it is not
necessary to check the thermal_zone_is_present() return value in
thermal_zone_device_update().  Namely, tz->state is equal to
TZ_STATE_FLAG_INIT initially and that flag is only cleared in
thermal_zone_init_complete() after adding tz to the list of thermal
zones, and thermal_zone_exit() sets TZ_STATE_FLAG_EXIT in tz->state
while removing tz from that list.  Thus tz->state is not TZ_STATE_READY
when tz is not in the list and the check mentioned above is redundant.

Accordingly, drop the redundant thermal_zone_is_present() check from
thermal_zone_device_update() and drop the former altogether because it
has no more users.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/3406806.aeNJFYEL58@rafael.j.wysocki

Author: rafaeljw

drivers/thermal/thermal_core.c

@@ -695,18 +695,12 @@ int thermal_zone_device_disable(struct thermal_zone_device *tz)
 }
 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 
-static bool thermal_zone_is_present(struct thermal_zone_device *tz)
-{
-	return !list_empty(&tz->node);
-}
-
 void thermal_zone_device_update(struct thermal_zone_device *tz,
 				enum thermal_notify_event event)
 {
 	guard(thermal_zone)(tz);
 
-	if (thermal_zone_is_present(tz))
-		__thermal_zone_device_update(tz, event);
+	__thermal_zone_device_update(tz, event);
 }
 EXPORT_SYMBOL_GPL(thermal_zone_device_update);