netfilter: nf_conntrack_sip: fix wrong memory initialisation

In commit 82de0be6 ("netfilter: Add helper array
register/unregister functions"),
struct nf_conntrack_helper sip[MAX_PORTS][4] was changed to
sip[MAX_PORTS * 4], so the memory init should have been changed to
memset(&sip[4 * i], 0, 4 * sizeof(sip[i]));

But as the sip[] table is allocated in the BSS, it is already set to 0

Fixes: 82de0be6 ("netfilter: Add helper array register/unregister functions")
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_sip.c

@@ -1628,8 +1628,6 @@ static int __init nf_conntrack_sip_init(void)
 		ports[ports_c++] = SIP_PORT;
 
 	for (i = 0; i < ports_c; i++) {
-		memset(&sip[i], 0, sizeof(sip[i]));
-
 		nf_ct_helper_init(&sip[4 * i], AF_INET, IPPROTO_UDP, "sip",
 				  SIP_PORT, ports[i], i, sip_exp_policy,
 				  SIP_EXPECT_MAX,