[zebra] Fix mistake in previous commit and further compile warnings/errors.

[zebra] Fix mistake in previous commit and further compile warnings/errors.

2005-11-24 Paul Jakma <paul.jakma@sun.com>

	* kernel_socket.h: New header for functions exported to sysctl
	  methods.
	* kernel_socket.c: include previous.
	  Remove static qualifier from couple of functions which are
	  used by sysctl methods, incorrectly added in previous commit.
	  Add a workaround for a bogus gcc warning to the RTA_ macros.
	* Makefile.am: Add kernel_socket.h to noinst_HEADERS
	* if_sysctl.c: include rt.h and kernel_socket.h and remove
	  redundant prototypes.
	* rtread_sysctl.c: ditto.
	  (route_read) fix mismatch of return values.
	* {rt,zserv,rib}.h: Include lib headers depended on.