[NETFILTER]: nf_conntrack: fix ct_extend ->move operation

The ->move operation has two bugs:

- It is called with the same extension as source and destination,
  so it doesn't update the new extension.

- The address of the old extension is calculated incorrectly,
  instead of (void *)ct->ext + ct->ext->offset[i] it uses
  ct->ext + ct->ext->offset[i].

Fixes a crash on x86_64 reported by Chuck Ebbert <cebbert@redhat.com>
and Thomas Woerner <twoerner@redhat.com>.

Tested-by: Thomas Woerner <twoerner@redhat.com>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
index 73b5711..49aac63 100644
--- a/include/net/netfilter/nf_conntrack_extend.h
+++ b/include/net/netfilter/nf_conntrack_extend.h
@@ -67,7 +67,7 @@
 	void (*destroy)(struct nf_conn *ct);
 	/* Called when realloacted (can be NULL).
 	   Contents has already been moved. */
-	void (*move)(struct nf_conn *ct, void *old);
+	void (*move)(void *new, void *old);
 
 	enum nf_ct_ext_id id;