Adds sanity check to Narsie pickcultist proc (#31937)

* Adds sanity check to Narsie pickcultist proc

* claned up src

* cleaned

code/modules/power/singularity/narsie.dm

@@ -142,7 +142,7 @@
 
 	for(var/mob/living/carbon/food in GLOB.living_mob_list) //we don't care about constructs or cult-Ians or whatever. cult-monkeys are fair game i guess
 		var/turf/pos = get_turf(food)
-		if(pos.z != src.z)
+		if(!pos || (pos.z != z))
 			continue
 
 		if(iscultist(food))
@@ -163,7 +163,7 @@
 		if(!ghost.client)
 			continue
 		var/turf/pos = get_turf(ghost)
-		if(pos.z != src.z)
+		if(!pos || (pos.z != z))
 			continue
 		cultists += ghost
 	if(cultists.len)