thermal: trip: Define for_each_trip() macro

Define a new macro for_each_trip() to be used by the thermal core code
and thermal governors for walking trips in a given thermal zone.

Modify for_each_thermal_trip() to use this macro instead of an open-
coded loop over trips.

No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

drivers/thermal/thermal_core.h

@@ -116,6 +116,9 @@ void __thermal_zone_device_update(struct thermal_zone_device *tz,
 				  enum thermal_notify_event event);
 
 /* Helpers */
+#define for_each_trip(__tz, __trip)	\
+	for (__trip = __tz->trips; __trip - __tz->trips < __tz->num_trips; __trip++)
+
 void __thermal_zone_set_trips(struct thermal_zone_device *tz);
 int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 			    struct thermal_trip *trip);

drivers/thermal/thermal_trip.c

@@ -13,10 +13,11 @@ int for_each_thermal_trip(struct thermal_zone_device *tz,
 			  int (*cb)(struct thermal_trip *, void *),
 			  void *data)
 {
-	int i, ret;
+	struct thermal_trip *trip;
+	int ret;
 
-	for (i = 0; i < tz->num_trips; i++) {
-		ret = cb(&tz->trips[i], data);
+	for_each_trip(tz, trip) {
+		ret = cb(trip, data);
 		if (ret)
 			return ret;
 	}