Fixes changeling runtime after ghosting (#37892)

code/modules/antagonists/changeling/changeling_power.dm

@@ -72,10 +72,10 @@
 
 //used in /mob/Stat()
 /obj/effect/proc_holder/changeling/proc/can_be_used_by(mob/user)
-	if(!user || QDELETED(user))
-		return 0
+	if(QDELETED(user))
+		return FALSE
 	if(!ishuman(user) && !ismonkey(user))
-		return 0
+		return FALSE
 	if(req_human && !ishuman(user))
-		return 0
-	return 1
+		return FALSE
+	return TRUE

code/modules/antagonists/changeling/powers/revive.dm

@@ -29,8 +29,12 @@
 	return TRUE
 
 /obj/effect/proc_holder/changeling/revive/can_be_used_by(mob/living/user)
+	. = ..()
+	if(!.)
+		return
+
 	if(user.has_trait(CHANGELING_DRAIN) || ((user.stat != DEAD) && !(user.has_trait(TRAIT_FAKEDEATH))))
 		var/datum/antagonist/changeling/changeling = user.mind.has_antag_datum(/datum/antagonist/changeling)
 		changeling.purchasedpowers -= src
-		return 0
-	. = ..()
+		return FALSE
+