The gpio_request_one() flags parameter was set to:

  GPIOF_DIR_OUT | !!brightness

GPIOF_DIR_OUT and GPIOF_DIR_IN are defined as below:
  GPIOF_DIR_OUT   (0 << 0)
  GPIOF_DIR_IN    (1 << 0)

So, when '!!brightness' is 1, the gpio pin can be set as input,
instead of output.

To prevent this problem, GPIOF_OUT_INIT flags should be used when
using gpio_request_one().
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>