Revert "gpio: pca953x: initialize ret to zero to avoid returning garbage"

This reverts commit 313b9a99.

This was already fixed by
commit bf62efeb
"gpio: pca954x: fix undefined error code from remove"

The latter is a better fix since it makes it easier to detect
erronous code by not assigning a default error code.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>