net: remove sk_init() helper

It seems sk_init() has no value today and even does strange things :

# grep . /proc/sys/net/core/?mem_*
/proc/sys/net/core/rmem_default:212992
/proc/sys/net/core/rmem_max:131071
/proc/sys/net/core/wmem_default:212992
/proc/sys/net/core/wmem_max:131071

We can remove it completely.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/socket.c

@@ -2600,12 +2600,6 @@ static int __init sock_init(void)
 	if (err)
 		goto out;
 
-	/*
-	 *      Initialize sock SLAB cache.
-	 */
-
-	sk_init();
-
 	/*
 	 *      Initialize skbuff SLAB cache
 	 */