drivers/video/backlight/l4f00242t03.c: return proper error in l4f00242t03_probe if...

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Alberto Panizzo <alberto@amarulasolutions.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>