ipaddr: fix a typo in error msg about SIOCGIFTXQLEN

The optname was wrong.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 16f92d9..2eb1a0a 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -163,7 +163,7 @@
 		memset(&ifr, 0, sizeof(ifr));
 		strcpy(ifr.ifr_name, rta_getattr_str(tb[IFLA_IFNAME]));
 		if (ioctl(s, SIOCGIFTXQLEN, &ifr) < 0) {
-			fprintf(f, "ioctl(SIOCGIFXQLEN) failed: %s\n", strerror(errno));
+			fprintf(f, "ioctl(SIOCGIFTXQLEN) failed: %s\n", strerror(errno));
 			close(s);
 			return;
 		}