more de-referencing

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

@@ -25,10 +25,13 @@
 /obj/item/weapon/flamethrower/Destroy()
 	if(weldtool)
 		qdel(weldtool)
+		weldtool = null
 	if(igniter)
 		qdel(igniter)
+		igniter = null
 	if(ptank)
 		qdel(ptank)
+		ptank = null
 	return ..()
 
 

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

@@ -15,6 +15,7 @@
 
 	Destroy()
 		qdel(smoke)
+		smoke = null
 		return ..()
 
 	prime()