staging: vt6656: main_usb.c ether_crc use kernel code

#include <net/cfg80211.h>

#include <linux/timer.h>

#include <linux/usb.h>

#include <linux/crc32.h>

#ifdef SIOCETHTOOL

#define DEVICE_ETHTOOL_IOCTL_SUPPORT

	return NETDEV_TX_OK;

}

static unsigned const ethernet_polynomial = 0x04c11db7U;

static inline u32 ether_crc(int length, unsigned char *data)

{

    int crc = -1;

    while(--length >= 0) {

        unsigned char current_octet = *data++;

        int bit;

        for (bit = 0; bit < 8; bit++, current_octet >>= 1) {

            crc = (crc << 1) ^

                ((crc < 0) ^ (current_octet & 1) ? ethernet_polynomial : 0);

        }

    }

    return crc;

}

/* find out the start position of str2 from str1 */

static unsigned char *kstrstr(const unsigned char *str1,

			      const unsigned char *str2) {