[LLC]: allow datagram recvmsg

LLC receive is broken for SOCK_DGRAM.
If an application does recv() on a datagram socket and there
is no data present, don't return "not connected". Instead, just
do normal datagram semantics.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/llc/af_llc.c

@@ -674,7 +674,7 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 
 	lock_sock(sk);
 	copied = -ENOTCONN;
-	if (sk->sk_state == TCP_LISTEN)
+	if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
 		goto out;
 
 	timeo = sock_rcvtimeo(sk, nonblock);
@@ -733,7 +733,7 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 			if (sk->sk_shutdown & RCV_SHUTDOWN)
 				break;
 
-			if (sk->sk_state == TCP_CLOSE) {
+			if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
 				if (!sock_flag(sk, SOCK_DONE)) {
 					/*
 					 * This occurs when user tries to read