netfilter: helper: Remove unused function declarations

Commit b1185090 ("netfilter: remove nf_conntrack_helper sysctl and modparam toggles")
leave these unused declarations.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

include/net/netfilter/nf_conntrack_helper.h

@@ -136,8 +136,6 @@ static inline void *nfct_help_data(const struct nf_conn *ct)
 	return (void *)help->data;
 }
 
-void nf_conntrack_helper_pernet_init(struct net *net);
-
 int nf_conntrack_helper_init(void);
 void nf_conntrack_helper_fini(void);
 
@@ -182,5 +180,4 @@ void nf_nat_helper_unregister(struct nf_conntrack_nat_helper *nat);
 int nf_nat_helper_try_module_get(const char *name, u16 l3num,
 				 u8 protonum);
 void nf_nat_helper_put(struct nf_conntrack_helper *helper);
-void nf_ct_set_auto_assign_helper_warned(struct net *net);
 #endif /*_NF_CONNTRACK_HELPER_H*/