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/net/sctp/protocol.c b/net/sctp/protocol.c
index 61b9fca..544a9b6 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -637,7 +637,7 @@
 		    " for cmd %d at entry %p\n", &sctp_addr_waitq, &addrw->a, addrw->state,
 		    addrw);
 
-#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#if IS_ENABLED(CONFIG_IPV6)
 		/* Now we send an ASCONF for each association */
 		/* Note. we currently don't handle link local IPv6 addressees */
 		if (addrw->a.sa.sa_family == AF_INET6) {