makes w_class use defines (#9848)

code/game/objects/structures/mop_bucket.dm

@@ -4,7 +4,7 @@
 	icon = 'icons/obj/janitor.dmi'
 	icon_state = "mopbucket"
 	density = 1
-	w_class = 3
+	w_class = ITEMSIZE_NORMAL
 	flags = OPENCONTAINER
 	var/amount_per_transfer_from_this = 5	//shit I dunno, adding this so syringes stop runtime erroring. --NeoFite
 	var/bucketsize = 360 //about 3x the size relative to a regular bucket.
@@ -44,4 +44,4 @@
 		var/obj/structure/janitorialcart/cart = loc
 		cart.update_icon()
 	else
-		update_icon()
+		update_icon()