netfilter: ip6t_LOG: fix a flaw in printing the MAC

The flaw was in skipping the second byte in MAC header due to increasing
the pointer AND indexed access starting at '1'.
Signed-off-by: Joerg Marx <joerg.marx@secunet.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

net/ipv6/netfilter/ip6t_LOG.c

@@ -410,7 +410,7 @@ static void dump_mac_header(struct sbuff *m,
 		if (p != NULL) {
 			sb_add(m, "%02x", *p++);
 			for (i = 1; i < len; i++)
-				sb_add(m, ":%02x", p[i]);
+				sb_add(m, ":%02x", *p++);
 		}
 		sb_add(m, " ");