fix I2C slave addressing

With the recent device handling changes the I2C slave addressing code
was broken. With current code, if a slave with the correct address is

not found on the bus the last scanned slave on the bus will be
addressed. This is wrong. Please find attached a patch to fix it.

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Acked-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>