HID: i2c-hid: Fix error handling

According to error handling in this function, it is likely that some
resources should be freed before returning.
Replace 'return ret', with 'goto err'.

While at it, remove some spaces at the beginning of the lines to be more
consistent.

Fixes: ead0687fe304a ("HID: i2c-hid: support regulator power on/off")

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>