net: Remove casts to same type

Adding casts of objects to the same type is unnecessary
and confusing for a human reader.

For example, this cast:

	int y;
	int *p = (int *)&y;

I used the coccinelle script below to find and remove these
unnecessary casts.  I manually removed the conversions this
script produces of casts with __force and __user.

@@
type T;
T *p;
@@

-	(T *)p
+	p

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 5577a44..11a863d 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -54,7 +54,7 @@
 };
 
 #define tipc_sk(sk) ((struct tipc_sock *)(sk))
-#define tipc_sk_port(sk) ((struct tipc_port *)(tipc_sk(sk)->p))
+#define tipc_sk_port(sk) (tipc_sk(sk)->p)
 
 #define tipc_rx_ready(sock) (!skb_queue_empty(&sock->sk->sk_receive_queue) || \
 			(sock->state == SS_DISCONNECTING))