lib: Fix race condition in shutdown of routemap

lib: Fix race condition in shutdown of routemap

When shutting down a daemon that uses an update
timer to handle route map processing, there
exists a race condition where if you change
a route map and then immediately shutdown
quagga before the update timer for the routemap
runs, you will be placed in a infinite loop.

This condition happens because this commit introduces
route map memory free'ing but never tests to see
if the to_be_processed flag has happened or not
before deleting:

commit 289d25016b79ed7908a29af7ba35e18f1ec6ed0a
Author: Lou Berger <lberger@labn.net>
Date:   Wed Apr 10 12:30:04 2013 -0700

    bgpd, lib: memory cleanups for valgrind, plus debug changes

Modify route_map_finish to explicitly turn off the to_be_processed
field.  As that we know we are going away if route_map_finish is
called.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Daniel Walton <dwalton@cumulusnetworks.com>