fix memory leaks for #quit while in tutorial

The new change to reset discoveries and monster-stats when exiting
the tutorial used dynamic data which wouldn't be freed if player
used #quit and declined to resume the regular game.

It turns out that such a leak was already present for start-of-game
inventory that gets stashed away during the tutorial.

In both cases, it could happen at most once per game so wasn't a big
deal as far as memory leaks go.

src/save.c

@@ -1210,6 +1210,7 @@ freedynamicdata(void)
     freeroleoptvals(); /* saveoptvals(&tnhfp) */
     cmdq_clear(CQ_CANNED);
     cmdq_clear(CQ_REPEAT);
+    free_tutorial(); /* (only needed if quiting while in tutorial) */
 
     /* some pointers in iflags */
     if (iflags.wc_font_map)