fix args to GetMonData

src/pokemon.c

@@ -6459,7 +6459,7 @@ void SetWildMonHeldItem(void)
 
         for (i = 0; i < count; i++)
         {
-            if (GetMonData(&gEnemyParty[i], MON_DATA_HELD_ITEM) != ITEM_NONE)
+            if (GetMonData(&gEnemyParty[i], MON_DATA_HELD_ITEM, NULL) != ITEM_NONE)
                 continue; // prevent ovewriting previously set item
             
             rnd = Random() % 100;