tcp: syncookies: do not use getnstimeofday()

#ifdef CONFIG_SYN_COOKIES

#include <linux/ktime.h>

/* Syncookies use a monotonic timer which increments every 64 seconds.

/* Syncookies use a monotonic timer which increments every 60 seconds.

 * This counter is used both as a hash input and partially encoded into

 * the cookie value.  A cookie is only validated further if the delta

 * between the current counter value and the encoded one is less than this,

 * i.e. a sent cookie is valid only at most for 128 seconds (or less if

 * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if

 * the counter advances immediately after a cookie is generated).

 */

#define MAX_SYNCOOKIE_AGE 2

static inline u32 tcp_cookie_time(void)

{

	struct timespec now;

	getnstimeofday(&now);

	return now.tv_sec >> 6; /* 64 seconds granularity */

	u64 val = get_jiffies_64();

	do_div(val, 60 * HZ);

	return val;

}

u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th,