Fix CHAMBER_FAN_MODE 0 build (#20621)

Marlin/src/module/temperature.cpp

@@ -1234,7 +1234,7 @@ void Temperature::manage_heater() {
 
         #if ENABLED(CHAMBER_FAN)
           #if CHAMBER_FAN_MODE == 0
-            fan_chamber_pwm = CHAMBER_FAN_BASE
+            fan_chamber_pwm = CHAMBER_FAN_BASE;
           #elif CHAMBER_FAN_MODE == 1
             fan_chamber_pwm = (temp_chamber.celsius > temp_chamber.target) ? (CHAMBER_FAN_BASE) + (CHAMBER_FAN_FACTOR) * (temp_chamber.celsius - temp_chamber.target) : 0;
           #elif CHAMBER_FAN_MODE == 2