ASoC: stm: Prevent potential division by zero in stm32_sai_mclk_round_rate()

This patch checks if div is less than or equal to zero (div <= 0). If
div is zero or negative, the function returns -EINVAL, ensuring the
division operation (*prate / div) is safe to perform.

Signed-off-by: Luo Yifan <luoyifan@cmss.chinamobile.com>
Link: https://patch.msgid.link/20241106014654.206860-1-luoyifan@cmss.chinamobile.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Luo Yifan

sound/soc/stm/stm32_sai_sub.c

@@ -378,8 +378,8 @@ static long stm32_sai_mclk_round_rate(struct clk_hw *hw, unsigned long rate,
 	int div;
 
 	div = stm32_sai_get_clk_div(sai, *prate, rate);
-	if (div < 0)
-		return div;
+	if (div <= 0)
+		return -EINVAL;
 
 	mclk->freq = *prate / div;