[NETFILTER]: H.323 conntrack: fix crash with CONFIG_IP_NF_CT_ACCT

H.323 connection tracking code calls ip_ct_refresh_acct() when
processing RCFs and URQs but passes NULL as the skb.
When CONFIG_IP_NF_CT_ACCT is enabled, the connection tracking core tries
to derefence the skb, which results in an obvious panic.
A similar fix was applied on the SIP connection tracking code some time
ago.

Signed-off-by: Faidon Liambotis <paravoid@debian.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/netfilter/ip_conntrack_helper_h323.c

@@ -1417,7 +1417,7 @@ static int process_rcf(struct sk_buff **pskb, struct ip_conntrack *ct,
 		DEBUGP
 		    ("ip_ct_ras: set RAS connection timeout to %u seconds\n",
 		     info->timeout);
-		ip_ct_refresh_acct(ct, ctinfo, NULL, info->timeout * HZ);
+		ip_ct_refresh(ct, *pskb, info->timeout * HZ);
 
 		/* Set expect timeout */
 		read_lock_bh(&ip_conntrack_lock);
@@ -1465,7 +1465,7 @@ static int process_urq(struct sk_buff **pskb, struct ip_conntrack *ct,
 	info->sig_port[!dir] = 0;
 
 	/* Give it 30 seconds for UCF or URJ */
-	ip_ct_refresh_acct(ct, ctinfo, NULL, 30 * HZ);
+	ip_ct_refresh(ct, *pskb, 30 * HZ);
 
 	return 0;
 }