pwm: vt8500: Introduce a local pwm_chip variable in .probe()

This simplifies converting the driver to pwmchip_alloc() as there is only
a single code line left that makes use of struct vt8500_chip::chip.

Link: https://lore.kernel.org/r/7d903b608609d46cf1ee1e06530f516f42af1ebb.1707900770.git.u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/pwm/pwm-vt8500.c

@@ -232,6 +232,7 @@ MODULE_DEVICE_TABLE(of, vt8500_pwm_dt_ids);
 
 static int vt8500_pwm_probe(struct platform_device *pdev)
 {
+	struct pwm_chip *chip;
 	struct vt8500_chip *vt8500;
 	struct device_node *np = pdev->dev.of_node;
 	int ret;
@@ -243,9 +244,10 @@ static int vt8500_pwm_probe(struct platform_device *pdev)
 	if (vt8500 == NULL)
 		return -ENOMEM;
 
-	vt8500->chip.dev = &pdev->dev;
-	vt8500->chip.ops = &vt8500_pwm_ops;
-	vt8500->chip.npwm = VT8500_NR_PWMS;
+	chip = &vt8500->chip;
+	chip->dev = &pdev->dev;
+	chip->ops = &vt8500_pwm_ops;
+	chip->npwm = VT8500_NR_PWMS;
 
 	vt8500->clk = devm_clk_get_prepared(&pdev->dev, NULL);
 	if (IS_ERR(vt8500->clk))
@@ -255,7 +257,7 @@ static int vt8500_pwm_probe(struct platform_device *pdev)
 	if (IS_ERR(vt8500->base))
 		return PTR_ERR(vt8500->base);
 
-	ret = devm_pwmchip_add(&pdev->dev, &vt8500->chip);
+	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret < 0)
 		return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");