drivers/video/backlight/lm3630a_bl.c: fix signedness bug in lm3630a_chip_init()

"rval" needs to be signed for the error handling to work.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
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>

drivers/video/backlight/lm3630a_bl.c

@@ -105,7 +105,7 @@ static int lm3630a_chip_init(struct lm3630a_chip *pchip)
 /* interrupt handling */
 static void lm3630a_delayed_func(struct work_struct *work)
 {
-	unsigned int rval;
+	int rval;
 	struct lm3630a_chip *pchip;
 
 	pchip = container_of(work, struct lm3630a_chip, work.work);