i2c: i2c-cros-ec-tunnel: Reduce logging noise

i2c: i2c-cros-ec-tunnel: Reduce logging noise

If an i2c access through i2c-cros-ec-tunnel returns an error, the following
log message is seen on the console.

cros-ec-i2c-tunnel ff200000.spi:ec@0:i2c-tunnel:
			Error parsing EC i2c message -121

This can happen a lot if, for example, the i2c-detect command is executed.

Since it is perfectly normal for an i2c controller to report an error,
drop the message. Also, report -ENXIO instead of -EREMOTEIO if the access
error is due to NAK from the device, and return -EIO instead of -EREMOTEIO
for other errors, as suggested in Documentation/i2c/fault-codes.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>