Remove obsolete netlink_firewall_socket and netlink_ip6fw_socket classes.

The implementation for NETLINK_FIREWALL and NETLINK_IP6_FW protocols
was removed from the kernel in commit
d16cf20e2f2f13411eece7f7fb72c17d141c4a84 ("netfilter: remove ip_queue
support") circa Linux 3.5.  Unless we need to retain compatibility
for kernels < 3.5, we can drop these classes from the policy altogether.

Possibly the neverallow rule in app.te should be augmented to include
the newer netlink security classes, similar to webview_zygote, but
that can be a separate change.

Test: policy builds

Change-Id: Iab9389eb59c96772e5fa87c71d0afc86fe99bb6b
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/private/app_neverallows.te b/private/app_neverallows.te
index 6928cd6..33670aa 100644
--- a/private/app_neverallows.te
+++ b/private/app_neverallows.te
@@ -50,8 +50,8 @@
 neverallow { untrusted_app ephemeral_app isolated_app } *:{ netlink_route_socket netlink_selinux_socket } ioctl;
 neverallow { untrusted_app ephemeral_app isolated_app } *:{
   socket netlink_socket packet_socket key_socket appletalk_socket
-  netlink_firewall_socket netlink_tcpdiag_socket netlink_nflog_socket
-  netlink_xfrm_socket netlink_audit_socket netlink_ip6fw_socket
+  netlink_tcpdiag_socket netlink_nflog_socket
+  netlink_xfrm_socket netlink_audit_socket
   netlink_dnrt_socket netlink_kobject_uevent_socket tun_socket
   netlink_iscsi_socket netlink_fib_lookup_socket netlink_connector_socket
   netlink_netfilter_socket netlink_generic_socket netlink_scsitransport_socket