ipadress: fix display of IPv6 peer address

Because only IPv4 was supported, the size was static. Now, IPv6 also supports
peer address.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>

ip/ipaddress.c

@@ -636,7 +636,8 @@ int print_addrinfo(const struct sockaddr_nl *who, struct nlmsghdr *n,
 					      abuf, sizeof(abuf)));
 
 		if (rta_tb[IFA_ADDRESS] == NULL ||
-		    memcmp(RTA_DATA(rta_tb[IFA_ADDRESS]), RTA_DATA(rta_tb[IFA_LOCAL]), 4) == 0) {
+		    memcmp(RTA_DATA(rta_tb[IFA_ADDRESS]), RTA_DATA(rta_tb[IFA_LOCAL]),
+			   ifa->ifa_family == AF_INET ? 4 : 16) == 0) {
 			fprintf(fp, "/%d ", ifa->ifa_prefixlen);
 		} else {
 			fprintf(fp, " peer %s/%d ",