Use TM constant in CanMonLearnTMTutor

src/party_menu.c

@@ -1962,7 +1962,7 @@ static u8 CanMonLearnTMTutor(struct Pokemon *mon, u16 item, u8 tutor)
 
     if (item >= ITEM_TM01)
     {
-        if (!CanMonLearnTMHM(mon, item - ITEM_TM01 - ((item > ITEM_TM100) ? 50 : 0)))
+        if (!CanMonLearnTMHM(mon, item - ITEM_TM01 - ((item > ITEM_TM100) ? NUM_TECHNICAL_MACHINES : 0)))
             return CANNOT_LEARN_MOVE;
         else
             move = ItemIdToBattleMoveId(item);