netfilter: nf_conntrack_h323: don't pass uninitialised l3num value

netfilter: nf_conntrack_h323: don't pass uninitialised l3num value

Mihail Milev reports: Error: UNINIT (CWE-457):
 net/netfilter/nf_conntrack_h323_main.c:1189:2: var_decl:
	Declaring variable "tuple" without initializer.
 net/netfilter/nf_conntrack_h323_main.c:1197:2:
	uninit_use_in_call: Using uninitialized value "tuple.src.l3num" when calling "__nf_ct_expect_find".
 net/netfilter/nf_conntrack_expect.c:142:2:
	read_value: Reading value "tuple->src.l3num" when calling "nf_ct_expect_dst_hash".

  1195|   	tuple.dst.protonum = IPPROTO_TCP;
  1196|
  1197|-> 	exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
  1198|   	if (exp && exp->master == ct)
  1199|   		return exp;

Switch this to a C99 initialiser and set the l3num value.

Fixes: f587de0e2feb ("[NETFILTER]: nf_conntrack/nf_nat: add H.323 helper port")
Signed-off-by: Florian Westphal <fw@strlen.de>