pwm: mediatek: Ensure to disable clocks in error path

After enabling the clocks each error path must disable the clocks again.
One of them failed to do so. Unify the error paths to use goto to make it
harder for future changes to add a similar bug.

Fixes: 7ca5994 ("pwm: mediatek: Prevent divide-by-zero in pwm_mediatek_config()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20250704172728.626815-2-u.kleine-koenig@baylibre.com
Cc: stable@vger.kernel.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>

Author: ukleinek

drivers/pwm/pwm-mediatek.c

@@ -130,8 +130,10 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		return ret;
 
 	clk_rate = clk_get_rate(pc->clk_pwms[pwm->hwpwm]);
-	if (!clk_rate)
-		return -EINVAL;
+	if (!clk_rate) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	/* Make sure we use the bus clock and not the 26MHz clock */
 	if (pc->soc->has_ck_26m_sel)
@@ -150,9 +152,9 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	}
 
 	if (clkdiv > PWM_CLK_DIV_MAX) {
-		pwm_mediatek_clk_disable(chip, pwm);
 		dev_err(pwmchip_parent(chip), "period of %d ns not supported\n", period_ns);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
@@ -169,9 +171,10 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	pwm_mediatek_writel(pc, pwm->hwpwm, reg_width, cnt_period);
 	pwm_mediatek_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
 
+out:
 	pwm_mediatek_clk_disable(chip, pwm);
 
-	return 0;
+	return ret;
 }
 
 static int pwm_mediatek_enable(struct pwm_chip *chip, struct pwm_device *pwm)