pwm: stm32-lp: Add check for clk_enable()

Add check for the return value of clk_enable() to catch the potential
error.
We used APP-Miner to find it.

Fixes: e70a540 ("pwm: Add STM32 LPTimer PWM driver")
Signed-off-by: Mingwei Zheng <zmw12306@gmail.com>
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
Link: https://lore.kernel.org/r/20241206215318.3402860-1-zmw12306@gmail.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>

Author: zmw12306

drivers/pwm/pwm-stm32-lp.c

@@ -167,8 +167,12 @@ static int stm32_pwm_lp_get_state(struct pwm_chip *chip,
 	regmap_read(priv->regmap, STM32_LPTIM_CR, &val);
 	state->enabled = !!FIELD_GET(STM32_LPTIM_ENABLE, val);
 	/* Keep PWM counter clock refcount in sync with PWM initial state */
-	if (state->enabled)
-		clk_enable(priv->clk);
+	if (state->enabled) {
+		int ret = clk_enable(priv->clk);
+
+		if (ret)
+			return ret;
+	}
 
 	regmap_read(priv->regmap, STM32_LPTIM_CFGR, &val);
 	presc = FIELD_GET(STM32_LPTIM_PRESC, val);