ASoC: stm: stm32_i2s: Fix calc_clk_div() error handling in determine_rate()

calc_clk_div() will only return a non-zero value (-EINVAL)
in case of error. On the other hand, req->rate is an unsigned long.
It seems quite odd that req->rate would be assigned a negative value,
which is clearly not a rate, and success would be returned.

Reinstate previous logic, which would just return error.

Fixes: afd529d74002 ("ASoC: stm: stm32_i2s: convert from round_rate() to determine_rate()")
Link: https://scan7.scan.coverity.com/#/project-view/53936/11354?selectedIssue=1647702

Signed-off-by: Sergio Perez Gonzalez <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/stm/stm32_i2s.c

···
 	int ret;
 
 	ret = stm32_i2s_calc_clk_div(i2s, req->best_parent_rate, req->rate);
-	if (ret) {
-		req->rate = ret;
-
-		return 0;
-	}
+	if (ret)
+		return ret;
 
 	mclk->freq = req->best_parent_rate / i2s->divider;