Fixes soap cleaning runtime

If you tried to clean an atom with soap, and that atom was deleted
before you finished cleaning, the message attempting to display its name
would runtime.

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

@@ -57,7 +57,7 @@
 		user << "<span class='notice'>You need to take that [target.name] off before cleaning it.</span>"
 	else if(istype(target,/obj/effect/decal/cleanable))
 		user.visible_message("<span class='warning'>[user] begins to scrub \the [target.name] out with [src].</span>")
-		if(do_after(user, src.cleanspeed))
+		if(do_after(user, src.cleanspeed) && target)
 			user << "<span class='notice'>You scrub \the [target.name] out.</span>"
 			del(target)
 	else