[bgpd] aspath_loop_check was broken, fix it and the aspath unit test code.

[bgpd] aspath_loop_check was broken, fix it and the aspath unit test code.

2006-08-06 Paul Jakma <paul.jakma@sun.com>

	* bgp_aspath.c: (aspath_loop_check) Fix the typo-bug which
	  essentially had disabled this check. Problem reported by
	  Bartek Kania <mrbk@gnarf.org> in [quagga-users 7388].
	* aspath_test.c: (validate) Fix the sense of the aspath_loop_check,
	  which was the wrong way around and had actually been testing for
	  aspath_loop_check to be buggy.