Make Death revive faster

Death will revive faster than the other riders.
Make all the riders revive after 67 turns, instead of 500.
There was practically a zero chance a rider would revive at 500,
so keep it somewhat sensible.

src/do.c

@@ -1960,9 +1960,7 @@ long timeout UNUSED;
 
         if (is_rider(mptr) && rn2(99)) { /* Rider usually tries again */
             action = REVIVE_MON;
-            for (when = 3L; when < 67L; when++)
-                if (!rn2(3))
-                    break;
+            when = rider_revival_time(body, TRUE);
         } else { /* rot this corpse away */
             You_feel("%sless hassled.", is_rider(mptr) ? "much " : "");
             action = ROT_CORPSE;