delays clearing the items out of the garbage queues when tick_checked

Since it already has the code necessary to handle doing it this way.

code/controllers/subsystem/garbage.dm

@@ -116,8 +116,9 @@ SUBSYSTEM_DEF(garbage)
 	for (var/ref in tobequeued)
 		count++
 		Queue(ref, GC_QUEUE_PREQUEUE+1)
+		tobequeued[count] = null
 		if (MC_TICK_CHECK)
-			break
+			return
 	if (count)
 		tobequeued.Cut(1,count+1)
 		count = 0
@@ -142,7 +143,7 @@ SUBSYSTEM_DEF(garbage)
 		if (!refID)
 			count++
 			if (MC_TICK_CHECK)
-				break
+				return
 			continue
 
 		var/GCd_at_time = queue[refID]
@@ -161,7 +162,7 @@ SUBSYSTEM_DEF(garbage)
 			reference_find_on_fail -= refID		//It's deleted we don't care anymore.
 			#endif
 			if (MC_TICK_CHECK)
-				break
+				return
 			continue
 
 		// Something's still referring to the qdel'd object.
@@ -184,13 +185,13 @@ SUBSYSTEM_DEF(garbage)
 			if (GC_QUEUE_HARDDELETE)
 				HardDelete(D)
 				if (MC_TICK_CHECK)
-					break
+					return
 				continue
 
 		Queue(D, level+1)
 
 		if (MC_TICK_CHECK)
-			break
+			return
 	if (count)
 		queue.Cut(1,count+1)
 		count = 0