[INET]: Remove no longer needed ->equal callback

Since this callback is used to check for conflicts in
hashtable when inserting a newly created frag queue, we can
do the same by checking for matching the queue with the 
argument, used to create one.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ipv6.h

@@ -378,7 +378,6 @@ static inline int ipv6_prefix_equal(const struct in6_addr *a1,
 }
 
 struct inet_frag_queue;
-int ip6_frag_equal(struct inet_frag_queue *q1, struct inet_frag_queue *q2);
 
 struct ip6_create_arg {
 	__be32 id;