Move temp_all_zero() to heaters_all_zero().

We need the power supply for the heaters, after all, not for
the temperature sensors. Some heaters (e.g. fans) don't even have
a temp sensor.

clock.c

@@ -8,7 +8,6 @@
 #include	"sersendf.h"
 #include	"dda_queue.h"
 #include	"watchdog.h"
-#include	"temp.h"
 #include	"timer.h"
 #include	"debug.h"
 #include	"heater.h"
@@ -24,7 +23,7 @@
 */
 static void clock_250ms(void) {
 	#ifndef	NO_AUTO_IDLE
-	if (temp_all_zero())	{
+  if (heaters_all_zero()) {
 		if (psu_timeout > (30 * 4)) {
 			power_off();
 		}

heater.c

@@ -443,6 +443,18 @@ void heater_set(heater_t index, uint8_t value) {
   power_on();
 }
 
+/** \brief check wether all heaters are off
+*/
+uint8_t heaters_all_zero() {
+  uint8_t i;
+
+  for (i = 0; i < NUM_HEATERS; i++) {
+    if (heaters_runtime[i].heater_output)
+      return 0;
+  }
+  return 255;
+}
+
 /** \brief turn off all heaters
 
 	for emergency stop

heater.h

@@ -21,6 +21,7 @@ void heater_save_settings(void);
 void heater_set(heater_t index, uint8_t value);
 void heater_tick(heater_t h, temp_type_t type, uint16_t current_temp, uint16_t target_temp);
 
+uint8_t heaters_all_zero(void);
 uint8_t heaters_all_off(void);
 
 void pid_set_p(heater_t index, int32_t p);

temp.c

@@ -341,17 +341,6 @@ uint16_t temp_get(temp_sensor_t index) {
 	return temp_sensors_runtime[index].last_read_temp;
 }
 
-uint8_t temp_all_zero() {
-	uint8_t i;
-	for (i = 0; i < NUM_TEMP_SENSORS; i++) {
-		if (temp_sensors[i].heater < NUM_HEATERS) {
-			if (temp_sensors_runtime[i].target_temp)
-				return 0;
-		}
-	}
-	return 255;
-}
-
 // extruder doesn't have sersendf_P
 #ifndef	EXTRUDER
 static void single_temp_print(temp_sensor_t index) {

temp.h

@@ -41,8 +41,6 @@ uint8_t	temp_achieved(void);
 void temp_set(temp_sensor_t index, uint16_t temperature);
 uint16_t temp_get(temp_sensor_t index);
 
-uint8_t temp_all_zero(void);
-
 void temp_print(temp_sensor_t index);
 
 #endif	/* _TEMP_H */