netfilter: conntrack: tell compiler to not inline nf_ct_resolve_clash

At this time compiler inlines it, but this code will not be executed
under normal conditions.

Also, no inlining allows to use "nf_ct_resolve_clash%return" perf probe.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_core.c

@@ -895,9 +895,10 @@ static void nf_ct_acct_merge(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
 }
 
 /* Resolve race on insertion if this protocol allows this. */
-static int nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
-			       enum ip_conntrack_info ctinfo,
-			       struct nf_conntrack_tuple_hash *h)
+static __cold noinline int
+nf_ct_resolve_clash(struct net *net, struct sk_buff *skb,
+		    enum ip_conntrack_info ctinfo,
+		    struct nf_conntrack_tuple_hash *h)
 {
 	/* This is the conntrack entry already in hashes that won race. */
 	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);