[AX25]: Fix ax25_get_socket locking

In an attempt to return a locked socket ax25_get_socket() was calling
lock_sock() with a spinlock held, bad idea.  Making matters worse it's
only user is running in bottom half context resulting in a potencial
attempt to sleep in bottom half context, so fix the locking there as well.
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ax25/af_ax25.c

@@ -180,8 +180,7 @@ struct sock *ax25_get_socket(ax25_address *my_addr, ax25_address *dest_addr,
 		    !ax25cmp(&s->dest_addr, dest_addr) &&
 		    s->sk->sk_type == type) {
 			sk = s->sk;
-			/* XXX Sleeps with spinlock held, use refcounts instead. XXX */
-			lock_sock(sk);
+			sock_hold(sk);
 			break;
 		}
 	}

net/ax25/ax25_in.c

@@ -275,6 +275,7 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 			/* Now find a suitable dgram socket */
 			sk = ax25_get_socket(&dest, &src, SOCK_DGRAM);
 			if (sk != NULL) {
+				bh_lock_sock(sk);
 				if (atomic_read(&sk->sk_rmem_alloc) >=
 				    sk->sk_rcvbuf) {
 					kfree_skb(skb);
@@ -286,7 +287,8 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 					if (sock_queue_rcv_skb(sk, skb) != 0)
 						kfree_skb(skb);
 				}
-				release_sock(sk);
+				bh_unlock_sock(sk);
+				sock_put(sk);
 			} else {
 				kfree_skb(skb);
 			}