if devfs_create failed because "eeprom0" already exists
of_parse_partitions must not be called, otherwise the already existing
eeprom gets assigned partitions that don't belog there.

Also free dummy clients in the error path and the write protect gpio
only if it is actually valid.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>