Removes weird arg in machinery get_room_area (#79645)

## About The Pull Request

This argument was only ever used as a pseudo dot operator. Not only that
but it was typed as `/area`, yet the only place that passed something to
it passed `/obj/machinery/light`s.

So I axed it.

code/game/machinery/_machinery.dm

@@ -512,19 +512,24 @@
 	return TRUE
 
 ///Get a valid powered area to reference for power use, mainly for wall-mounted machinery that isn't always mapped directly in a powered location.
-/obj/machinery/proc/get_room_area(area/machine_room)
+/obj/machinery/proc/get_room_area()
 	var/area/machine_area = get_area(src)
-	if(!machine_area.always_unpowered) ///check our loc first to see if its a powered area
-		machine_room = machine_area
-		return machine_room
-	var/turf/mounted_wall = get_step(src,dir)
-	if (mounted_wall && istype(mounted_wall, /turf/closed))
+	if(isnull(machine_area))
+		return null // ??
+
+	// check our own loc first to see if its a powered area
+	if(!machine_area.always_unpowered)
+		return machine_area
+
+	// loc area wasn't good, checking adjacent wall for a good area to use
+	var/turf/mounted_wall = get_step(src, dir)
+	if(isclosedturf(mounted_wall))
 		var/area/wall_area = get_area(mounted_wall)
-		if(!wall_area.always_unpowered) //loc area wasn't good, checking adjacent wall for a good area to use
-			machine_room = wall_area
-			return machine_room
-	machine_room = machine_area ///couldn't find a proper powered area on loc or adjacent wall, defaulting back to loc and blaming mappers
-	return machine_room
+		if(!wall_area.always_unpowered)
+			return wall_area
+
+	// couldn't find a proper powered area on loc or adjacent wall, defaulting back to loc and blaming mappers
+	return machine_area
 
 ///makes this machine draw power from its area according to which use_power mode it is set to
 /obj/machinery/proc/update_current_power_usage()

code/modules/power/lighting/light.dm

@@ -101,7 +101,7 @@
 			qdel(on_turf)
 
 	if(!mapload) //sync up nightshift lighting for player made lights
-		var/area/our_area = get_room_area(src)
+		var/area/our_area = get_room_area()
 		var/obj/machinery/power/apc/temp_apc = our_area.apc
 		nightshift_enabled = temp_apc?.nightshift_lights
 
@@ -131,7 +131,7 @@
 	update(trigger = FALSE)
 
 /obj/machinery/light/Destroy()
-	var/area/local_area = get_room_area(src)
+	var/area/local_area = get_room_area()
 	if(local_area)
 		on = FALSE
 	QDEL_NULL(cell)
@@ -154,7 +154,7 @@
 /obj/machinery/light/update_icon_state()
 	switch(status) // set icon_states
 		if(LIGHT_OK)
-			var/area/local_area =get_room_area(src)
+			var/area/local_area = get_room_area()
 			if(low_power_mode || major_emergency || (local_area?.fire))
 				icon_state = "[base_state]_emergency"
 			else
@@ -174,7 +174,7 @@
 
 	. += emissive_appearance(overlay_icon, "[base_state]", src, alpha = src.alpha)
 
-	var/area/local_area = get_room_area(src)
+	var/area/local_area = get_room_area()
 
 	if(low_power_mode || major_emergency || (local_area?.fire))
 		. += mutable_appearance(overlay_icon, "[base_state]_emergency")
@@ -190,7 +190,7 @@
 	. = ..()
 	if(!.)
 		return
-	var/area/our_area = get_room_area(src)
+	var/area/our_area = get_room_area()
 	RegisterSignal(our_area, COMSIG_AREA_FIRE_CHANGED, PROC_REF(handle_fire))
 
 /obj/machinery/light/on_enter_area(datum/source, area/area_to_register)
@@ -220,7 +220,7 @@
 			color_set = color
 		if(reagents)
 			START_PROCESSING(SSmachines, src)
-		var/area/local_area =get_room_area(src)
+		var/area/local_area = get_room_area()
 		if (local_area?.fire)
 			color_set = fire_colour
 			brightness_set = fire_brightness
@@ -262,7 +262,7 @@
 		static_power_used = 0
 	else if(on) //Light is on, just recalculate usage
 		var/static_power_used_new = 0
-		var/area/local_area = get_room_area(src)
+		var/area/local_area = get_room_area()
 		if (nightshift_enabled && !local_area?.fire)
 			static_power_used_new = nightshift_brightness * nightshift_light_power * power_consumption_rate
 		else
@@ -447,13 +447,13 @@
 // returns if the light has power /but/ is manually turned off
 // if a light is turned off, it won't activate emergency power
 /obj/machinery/light/proc/turned_off()
-	var/area/local_area = get_room_area(src)
+	var/area/local_area = get_room_area()
 	return !local_area.lightswitch && local_area.power_light || flickering
 
 // returns whether this light has power
 // true if area has power and lightswitch is on
 /obj/machinery/light/proc/has_power()
-	var/area/local_area =get_room_area(src)
+	var/area/local_area = get_room_area()
 	return local_area.lightswitch && local_area.power_light
 
 // returns whether this light has emergency power
@@ -655,7 +655,7 @@
 // called when area power state changes
 /obj/machinery/light/power_change()
 	SHOULD_CALL_PARENT(FALSE)
-	var/area/local_area =get_room_area(src)
+	var/area/local_area = get_room_area()
 	set_on(local_area.lightswitch && local_area.power_light)
 
 // called when heated