re-do the #H260 lava fix

Instead of duplicating the bits of spoteffects() which are relevant
to pools of water and lava when standing still, split spoteffects in two
in order to call the relevant half directly.

src/allmain.c

@@ -322,7 +322,7 @@ boolean resuming;
 		!(moves % 15) && !rn2(2)) do_vicinity_map();
 	    if (u.utrap && u.utraptype == TT_LAVA) sink_into_lava();
 	    /* when/if hero escapes from lava, he can't just stay there */
-	    else if (!u.umoved) stayeffects();
+	    else if (!u.umoved) (void)pooleffects(FALSE);
 
 	} /* actual time passed */