i2c-nomadik: corrrect returned error numbers

The code was returning bad error numbers or just -1 in some cases.

Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>