media: s5p-jpeg: don't return a value on a void function

Building this driver on arm64 gives this warning:
	drivers/media/platform/s5p-jpeg/jpeg-hw-exynos3250.c:430:16: error: return expression in void function

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>