Converts Most Destroys to use QDEL_NULL

code/datums/action.dm

@@ -29,8 +29,7 @@
 		Remove(owner)
 	if(target)
 		target = null
-	qdel(button)
-	button = null
+	QDEL_NULL(button)
 	return ..()
 
 /datum/action/proc/Grant(mob/M)

code/datums/spell.dm

@@ -100,7 +100,7 @@ var/list/spells = typesof(/obj/effect/proc_holder/spell) //needed for the badmin
 	var/action_icon = 'icons/mob/actions.dmi'
 	var/action_icon_state = "spell_default"
 	var/action_background_icon_state = "bg_spell"
-	
+
 	var/sound = null //The sound the spell makes when it is cast
 
 /obj/effect/proc_holder/spell/proc/cast_check(skipcharge = 0, mob/living/user = usr) //checks if the spell can be cast based on its settings; skipcharge is used when an additional cast_check is called inside the spell
@@ -184,8 +184,8 @@ var/list/spells = typesof(/obj/effect/proc_holder/spell) //needed for the badmin
 			user.visible_message(invocation, invocation_emote_self) //same style as in mob/living/emote.dm
 
 /obj/effect/proc_holder/spell/proc/playMagSound()
-	playsound(get_turf(usr), sound,50,1)			
-			
+	playsound(get_turf(usr), sound,50,1)
+
 /obj/effect/proc_holder/spell/New()
 	..()
 	action = new(src)
@@ -194,8 +194,7 @@ var/list/spells = typesof(/obj/effect/proc_holder/spell) //needed for the badmin
 	charge_counter = charge_max
 
 /obj/effect/proc_holder/spell/Destroy()
-	qdel(action)
-	action = null
+	QDEL_NULL(action)
 	return ..()
 
 /obj/effect/proc_holder/spell/Click()
@@ -223,10 +222,10 @@ var/list/spells = typesof(/obj/effect/proc_holder/spell) //needed for the badmin
 	spawn(0)
 		if(charge_type == "recharge" && recharge)
 			start_recharge()
-			
+
 	if(sound)
-		playMagSound()			
-			
+		playMagSound()
+
 	if(prob(critfailchance))
 		critfail(targets)
 	else