thermal: trivial: fix typo in comment

Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NEduardo Valentin <edubezval@gmail.com>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>

drivers/thermal/thermal_core.c

@@ -465,7 +465,7 @@ static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 }
 
 /**
- * thermal_zone_get_temp() - returns its the temperature of thermal zone
+ * thermal_zone_get_temp() - returns the temperature of a thermal zone
  * @tz: a valid pointer to a struct thermal_zone_device
  * @temp: a valid pointer to where to store the resulting temperature.
  *