clean up wait_for_heatup use

Marlin/src/module/temperature.cpp

@@ -910,6 +910,7 @@ volatile bool Temperature::raw_temps_ready = false;
         return false;
       }
 
+      wait_for_heatup = false;
       return true;
     };
 
@@ -992,6 +993,7 @@ volatile bool Temperature::raw_temps_ready = false;
     uint16_t sample_distance = 1;
     float t1_time = 0;
 
+    wait_for_heatup = true;
     for (;;) { // Can be interrupted with M108
       if (!housekeeping(ms, current_temp, next_report_ms)) return;
 
@@ -1048,6 +1050,7 @@ volatile bool Temperature::raw_temps_ready = false;
     #endif
     float last_temp = current_temp;
 
+    wait_for_heatup = true;
     for (;;) { // Can be interrupted with M108
       if (!housekeeping(ms, current_temp, next_report_ms)) return;
 
@@ -4127,6 +4130,7 @@ void Temperature::isr() {
 
       } while (wait_for_heatup && TEMP_CONDITIONS);
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         #if HAS_DWIN_E3V2_BASIC
@@ -4265,6 +4269,7 @@ void Temperature::isr() {
 
       } while (wait_for_heatup && TEMP_BED_CONDITIONS);
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();
@@ -4343,6 +4348,7 @@ void Temperature::isr() {
         }
       }
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();
@@ -4442,6 +4448,7 @@ void Temperature::isr() {
         }
       } while (wait_for_heatup && TEMP_CHAMBER_CONDITIONS);
 
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();
@@ -4528,6 +4535,7 @@ void Temperature::isr() {
           first_loop = false;
         #endif // TEMP_COOLER_RESIDENCY_TIME > 0
 
+        // Prevent a wait-forever situation if R is misused i.e. M191 R0
         if (wants_to_cool) {
           // Break after MIN_COOLING_SLOPE_TIME_CHAMBER seconds
           // if the temperature did not drop at least MIN_COOLING_SLOPE_DEG_CHAMBER
@@ -4540,7 +4548,7 @@ void Temperature::isr() {
 
       } while (wait_for_heatup && TEMP_COOLER_CONDITIONS);
 
-      // Prevent a wait-forever situation if R is misused i.e. M191 R0
+      // If wait_for_heatup is set, temperature was reached, no cancel
       if (wait_for_heatup) {
         wait_for_heatup = false;
         ui.reset_status();