tcpv6: fix option space offsets with md5

More breakage :-), part of timestamps just were previously
overwritten.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index e8b0fdd..dd7bdde 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1088,7 +1088,7 @@
 		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 		*topt++ = htonl(tcp_time_stamp);
-		*topt = htonl(ts);
+		*topt++ = htonl(ts);
 	}
 
 #ifdef CONFIG_TCP_MD5SIG