net: remove clear_sk() method

We no longer use this handler, we can delete it.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -1020,7 +1020,6 @@ struct proto {
 	void			(*unhash)(struct sock *sk);
 	void			(*rehash)(struct sock *sk);
 	int			(*get_port)(struct sock *sk, unsigned short snum);
-	void			(*clear_sk)(struct sock *sk, int size);
 
 	/* Keeping track of sockets in use */
 #ifdef CONFIG_PROC_FS

net/core/sock.c

@@ -1326,12 +1326,8 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
 		if (!sk)
 			return sk;
-		if (priority & __GFP_ZERO) {
-			if (prot->clear_sk)
-				prot->clear_sk(sk, prot->obj_size);
-			else
-				sk_prot_clear_nulls(sk, prot->obj_size);
-		}
+		if (priority & __GFP_ZERO)
+			sk_prot_clear_nulls(sk, prot->obj_size);
 	} else
 		sk = kmalloc(prot->obj_size, priority);