[PATCH] ipt_ECN corrupt checksum fix

Nasty bug, caught while writing the ECN target test.  Corrupts
checksums of packets when target is used on them.

Let this be a warning on the evils of casts.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

net/ipv4/netfilter/ipt_ECN.c

@@ -67,7 +67,7 @@ set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo, int inward)
 
 	if (einfo->operation & IPT_ECN_OP_SET_CWR)
 		th->cwr = einfo->proto.tcp.cwr;
-	diffs[1] = ((u_int16_t *)&th)[6];
+	diffs[1] = ((u_int16_t *)th)[6];
 
 	/* Only mangle if it's changed. */
 	if (diffs[0] != diffs[1]) {