netfilter: nf_conntrack: remove unnecessary function declaration

This patch removes nf_ct_ipv4_ct_gather_frags() method declaration from
include/net/netfilter/ipv4/nf_conntrack_ipv4.h, since it is unused in
the Linux kernel.
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netfilter/ipv4/nf_conntrack_ipv4.h

@@ -9,8 +9,6 @@
 #ifndef _NF_CONNTRACK_IPV4_H
 #define _NF_CONNTRACK_IPV4_H
 
-/* Returns new sk_buff, or NULL */
-struct sk_buff *nf_ct_ipv4_ct_gather_frags(struct sk_buff *skb);
 
 extern struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4;