f2fs: compress: don't handle non-compressed data in workqueue

If bio has no compressed data, we don't need to handle end_io work in
workqueue, instead, it should just let interrupter handle it directly
to speed up IO response.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>