net: use IS_ENABLED(CONFIG_IPV6)

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/protocol.h b/include/net/protocol.h
index e182e13..875f489 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -25,7 +25,7 @@
 #define _PROTOCOL_H
 
 #include <linux/in6.h>
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#if IS_ENABLED(CONFIG_IPV6)
 #include <linux/ipv6.h>
 #endif
 
@@ -46,7 +46,7 @@
 				netns_ok:1;
 };
 
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#if IS_ENABLED(CONFIG_IPV6)
 struct inet6_protocol {
 	int	(*handler)(struct sk_buff *skb);
 
@@ -91,7 +91,7 @@
 
 extern const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
 
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#if IS_ENABLED(CONFIG_IPV6)
 extern const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
 #endif
 
@@ -100,7 +100,7 @@
 extern void	inet_register_protosw(struct inet_protosw *p);
 extern void	inet_unregister_protosw(struct inet_protosw *p);
 
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#if IS_ENABLED(CONFIG_IPV6)
 extern int	inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
 extern int	inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
 extern int	inet6_register_protosw(struct inet_protosw *p);