a few qdel_null's

code/game/objects/items/weapons/RCD.dm

@@ -279,8 +279,7 @@ RCD
 					return 0
 				activate()
 				var/turf/T1 = get_turf(A)
-				qdel(A)
-				A = null
+				QDEL_NULL(A)
 				for(var/obj/structure/window/W in T1.contents)
 					W.disassembled = 1
 					W.density = 0

code/game/objects/items/weapons/grenades/smokebomb.dm

@@ -14,8 +14,7 @@
 		src.smoke.attach(src)
 
 	Destroy()
-		qdel(smoke)
-		smoke = null
+		QDEL_NULL(smoke)
 		return ..()
 
 	prime()