[MIRROR] Fixes changelings retaining fake brains on de-changelining (#5248)

* Merge pull request #34872 from AnturK/theresabraininymyhead

Fixes changelings retaining fake brains on de-changelining

* Fixes changelings retaining fake brains on de-changelining

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

@@ -28,7 +28,13 @@
 			C.regenerate_limbs(1)
 		C.regenerate_organs()
 		if(!user.getorganslot(ORGAN_SLOT_BRAIN))
-			var/obj/item/organ/brain/changeling_brain/B = new()
+			var/obj/item/organ/brain/B
+			if(C.has_dna() && C.dna.species.mutant_brain)
+				B = new C.dna.species.mutant_brain()
+			else
+				B = new()
+			B.vital = FALSE
+			B.decoy_override = TRUE
 			B.Insert(C)
 	if(ishuman(user))
 		var/mob/living/carbon/human/H = user

code/modules/mob/living/brain/brain_item.dm

@@ -15,10 +15,6 @@
 
 	var/list/datum/brain_trauma/traumas = list()
 
-/obj/item/organ/brain/changeling_brain
-	vital = FALSE
-	decoy_override = TRUE
-
 /obj/item/organ/brain/Insert(mob/living/carbon/C, special = 0,no_id_transfer = FALSE)
 	..()