tipc: silence sparse warnings

Eliminate below sparse warnings:

net/tipc/link.c:1210:37: warning: cast removes address space of expression
net/tipc/link.c:1218:59: warning: incorrect type in argument 2 (different address spaces)
net/tipc/link.c:1218:59:    expected void const [noderef] <asn:1>*from
net/tipc/link.c:1218:59:    got unsigned char const [usertype] *[assigned] sect_crs
net/tipc/socket.c:341:49: warning: Using plain integer as NULL pointer
net/tipc/socket.c:1371:36: warning: Using plain integer as NULL pointer
net/tipc/socket.c:1694:57: warning: Using plain integer as NULL pointer

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Andreas Bofjäll <andreas.bofjall@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/link.c

@@ -1160,7 +1160,7 @@ static int link_send_sections_long(struct tipc_port *sender,
 	struct tipc_msg fragm_hdr;
 	struct sk_buff *buf, *buf_chain, *prev;
 	u32 fragm_crs, fragm_rest, hsz, sect_rest;
-	const unchar *sect_crs;
+	const unchar __user *sect_crs;
 	int curr_sect;
 	u32 fragm_no;
 	int res = 0;
@@ -1202,7 +1202,7 @@ again:
 
 		if (!sect_rest) {
 			sect_rest = msg_sect[++curr_sect].iov_len;
-			sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
+			sect_crs = msg_sect[curr_sect].iov_base;
 		}
 
 		if (sect_rest < fragm_rest)

net/tipc/socket.c

@@ -338,7 +338,7 @@ static int release(struct socket *sock)
 		buf = __skb_dequeue(&sk->sk_receive_queue);
 		if (buf == NULL)
 			break;
-		if (TIPC_SKB_CB(buf)->handle != 0)
+		if (TIPC_SKB_CB(buf)->handle != NULL)
 			kfree_skb(buf);
 		else {
 			if ((sock->state == SS_CONNECTING) ||
@@ -1364,7 +1364,7 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf)
 		return TIPC_ERR_OVERLOAD;
 
 	/* Enqueue message */
-	TIPC_SKB_CB(buf)->handle = 0;
+	TIPC_SKB_CB(buf)->handle = NULL;
 	__skb_queue_tail(&sk->sk_receive_queue, buf);
 	skb_set_owner_r(buf, sk);
 
@@ -1687,7 +1687,7 @@ restart:
 		/* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
 		buf = __skb_dequeue(&sk->sk_receive_queue);
 		if (buf) {
-			if (TIPC_SKB_CB(buf)->handle != 0) {
+			if (TIPC_SKB_CB(buf)->handle != NULL) {
 				kfree_skb(buf);
 				goto restart;
 			}