ipv4: Use IS_ERR_OR_NULL().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/af_inet.c

@@ -1333,7 +1333,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 		segs = ops->callbacks.gso_segment(skb, features);
 	rcu_read_unlock();
 
-	if (!segs || IS_ERR(segs))
+	if (IS_ERR_OR_NULL(segs))
 		goto out;
 
 	skb = segs;

net/ipv4/tcp.c

@@ -3243,7 +3243,7 @@ __tcp_alloc_md5sig_pool(struct sock *sk)
 		struct crypto_hash *hash;
 
 		hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
-		if (!hash || IS_ERR(hash))
+		if (IS_ERR_OR_NULL(hash))
 			goto out_free;
 
 		per_cpu_ptr(pool, cpu)->md5_desc.tfm = hash;

net/ipv4/udp.c

@@ -971,7 +971,7 @@ back_from_confirm:
 				  sizeof(struct udphdr), &ipc, &rt,
 				  msg->msg_flags);
 		err = PTR_ERR(skb);
-		if (skb && !IS_ERR(skb))
+		if (!IS_ERR_OR_NULL(skb))
 			err = udp_send_skb(skb, fl4);
 		goto out;
 	}