ALSA: sb: Use DIV_ROUND_UP() instead of open-coding it

Use DIV_ROUND_UP() instead of open-coding it, which intents and makes
it more clear what is going on for the casual reviewer.

The Coccinelle references Commit e4d8aef2

 ("ALSA: usb: Use
DIV_ROUND_UP() instead of open-coding it").

Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Link: https://lore.kernel.org/r/20220927141110.18033-1-shangxiaojing@huawei.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>