I2C: JZ4780: Fix bug for Ingenic X1000.

Only send "X1000_I2C_DC_STOP" when last byte, or it will cause
error when I2C write operation which should look like this:

device_addr + w, reg_addr, data;

But without this patch, it looks like this:

device_addr + w, reg_addr, device_addr + w, data;

Fixes: 21575a7a ("I2C: JZ4780: Add support for the X1000.")
Reported-by: 杨文龙 (Yang Wenlong) <ywltyut@sina.cn>
Tested-by: 杨文龙 (Yang Wenlong) <ywltyut@sina.cn>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-jz4780.c

@@ -525,8 +525,8 @@ static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id)
 				i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
 				data = *i2c->wbuf;
 				data &= ~JZ4780_I2C_DC_READ;
-				if ((!i2c->stop_hold) && (i2c->cdata->version >=
-						ID_X1000))
+				if ((i2c->wt_len == 1) && (!i2c->stop_hold) &&
+						(i2c->cdata->version >= ID_X1000))
 					data |= X1000_I2C_DC_STOP;
 				jz4780_i2c_writew(i2c, JZ4780_I2C_DC, data);
 				i2c->wbuf++;