backlight: lm3630a: Return 0 on success in update_status functions

backlight: lm3630a: Return 0 on success in update_status functions

BugLink: https://bugs.launchpad.net/bugs/1863019
[ Upstream commit d3f48ec0954c6aac736ab21c34a35d7554409112 ]

lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status()
both return the brightness value if the brightness was successfully
updated. Writing to these attributes via sysfs would cause a 'Bad
address' error to be returned. These functions should return 0 on
success, so let's change it to correct that error.

Fixes: 28e64a68a2ef ("backlight: lm3630: apply chip revision")
Signed-off-by: Brian Masney <masneyb@onstation.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>