ipv6: use IS_ENABLED()

#if defined(CONFIG_FOO) || defined(CONFIG_FOO_MODULE)

can be replaced by

#if IS_ENABLED(CONFIG_FOO)

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index aece3e7..e10c77b 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -538,8 +538,7 @@
 	to->tc_index = from->tc_index;
 #endif
 	nf_copy(to, from);
-#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
-    defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
 	to->nf_trace = from->nf_trace;
 #endif
 	skb_copy_secmark(to, from);
@@ -564,7 +563,7 @@
 			found_rhdr = 1;
 			break;
 		case NEXTHDR_DEST:
-#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
 			if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
 				break;
 #endif