(deli, do_demo, lnd_sweep, guerrilla): Saturate items at ITEM_MAX.

With variables, item increases beyond the capacity of variables
(65535) were ignored here.

This should cover all item changes not going through putvec().

src/lib/subs/lndsub.c

@@ -715,7 +715,7 @@ lnd_sweep(struct emp_qelem *land_list, int verbose, int takemob,
 		mines--;
 		if (lshells < max)
 		    ++lshells;
-		else
+		else if (sshells < ITEM_MAX)
 		    ++sshells;
 	    }
 	}