The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Acked-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>