drivers/video/backlight/lm3630a_bl.c: add missing destroy_workqueue() on error in lm3630a_intr_config()

Add the missing destroy_workqueue() before return from
lm3630a_intr_config() in the error handling case.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>