selinux: recognize netlink messages for 'ip addrlabel'

In enforcing mode '/sbin/ip addrlabel' results in a SELinux error:
type=SELINUX_ERR msg=audit(1225698822.073:42): SELinux:  unrecognized
netlink message type=74 for sclass=43

The problem is missing RTM_*ADDRLABEL entries in SELinux's netlink
message types table.

Reported in https://bugzilla.redhat.com/show_bug.cgi?id=469423



Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>