Disable IPv6 support code in vxlan when building with uClibc configured without
IPv6 support.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

diff -Nura iproute2-3.14.0/ip/iplink_vxlan.c iproute2-3.14.0-noipv6/ip/iplink_vxlan.c
--- iproute2-3.14.0/ip/iplink_vxlan.c	2014-04-11 21:48:41.000000000 -0300
+++ iproute2-3.14.0-noipv6/ip/iplink_vxlan.c	2014-04-14 08:36:22.638235721 -0300
@@ -9,6 +9,11 @@
  * Authors:     Stephen Hemminger <shemminger@vyatta.com
  */
 
+#include <features.h>
+#if defined(__UCLIBC__) && !defined (__UCLIBC_HAS_IPV6__)
+#define NO_IPV6
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -188,12 +193,14 @@
 		return -1;
 	}
 
+#ifndef NO_IPV6
 	if ((gaddr && daddr) ||
 		(memcmp(&gaddr6, &in6addr_any, sizeof(gaddr6)) &&
 		 memcmp(&daddr6, &in6addr_any, sizeof(daddr6)))) {
 		fprintf(stderr, "vxlan: both group and remote cannot be specified\n");
 		return -1;
 	}
+#endif
 
 	if (!dst_port_set) {
 		fprintf(stderr, "vxlan: destination port not specified\n"
@@ -208,15 +215,19 @@
 		addattr_l(n, 1024, IFLA_VXLAN_GROUP, &gaddr, 4);
 	else if (daddr)
 		addattr_l(n, 1024, IFLA_VXLAN_GROUP, &daddr, 4);
+#ifndef NO_IPV6
 	if (memcmp(&gaddr6, &in6addr_any, sizeof(gaddr6)) != 0)
 		addattr_l(n, 1024, IFLA_VXLAN_GROUP6, &gaddr6, sizeof(struct in6_addr));
 	else if (memcmp(&daddr6, &in6addr_any, sizeof(daddr6)) != 0)
 		addattr_l(n, 1024, IFLA_VXLAN_GROUP6, &daddr6, sizeof(struct in6_addr));
+#endif
 
 	if (saddr)
 		addattr_l(n, 1024, IFLA_VXLAN_LOCAL, &saddr, 4);
+#ifndef NO_IPV6
 	else if (memcmp(&saddr6, &in6addr_any, sizeof(saddr6)) != 0)
 		addattr_l(n, 1024, IFLA_VXLAN_LOCAL6, &saddr6, sizeof(struct in6_addr));
+#endif
 
 	if (link)
 		addattr32(n, 1024, IFLA_VXLAN_LINK, link);
@@ -275,6 +286,7 @@
 	} else if (tb[IFLA_VXLAN_GROUP6]) {
 		struct in6_addr addr;
 		memcpy(&addr, RTA_DATA(tb[IFLA_VXLAN_GROUP6]), sizeof(struct in6_addr));
+#ifndef NO_IPV6
 		if (memcmp(&addr, &in6addr_any, sizeof(addr)) != 0) {
 			if (IN6_IS_ADDR_MULTICAST(&addr))
 				fprintf(f, "group %s ",
@@ -283,6 +295,7 @@
 				fprintf(f, "remote %s ",
 					format_host(AF_INET6, sizeof(struct in6_addr), &addr, s1, sizeof(s1)));
 		}
+#endif
 	}
 
 	if (tb[IFLA_VXLAN_LOCAL]) {
@@ -293,9 +306,11 @@
 	} else if (tb[IFLA_VXLAN_LOCAL6]) {
 		struct in6_addr addr;
 		memcpy(&addr, RTA_DATA(tb[IFLA_VXLAN_LOCAL6]), sizeof(struct in6_addr));
+#ifndef NO_IPV6
 		if (memcmp(&addr, &in6addr_any, sizeof(addr)) != 0)
 			fprintf(f, "local %s ",
 				format_host(AF_INET6, sizeof(struct in6_addr), &addr, s1, sizeof(s1)));
+#endif
 	}
 
 	if (tb[IFLA_VXLAN_LINK] &&