i2c-i801: Don't use the block buffer for I2C block writes

commit c074c39d62306efa5ba7c69c1a1531bc7333d252 upstream.

Experience has shown that the block buffer can only be used for SMBus
(not I2C) block transactions, even though the datasheet doesn't
mention this limitation.

Reported-by: Felix Rubinstein <felixru@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Oleg Ryjkov <oryjkov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>