sock_diag: do not broadcast raw socket destruction

Diag intends to broadcast tcp_sk and udp_sk socket destruction.
Testing sk->sk_protocol for IPPROTO_TCP/IPPROTO_UDP alone is not
sufficient for this. Raw sockets can have the same type.

Add a test for sk->sk_type.

Fixes: eb4cb008

 ("sock_diag: define destruction multicast groups")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>