pwm: Remove unnecessary check before of_node_put()

The of_node_put() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/core.c

@@ -192,7 +192,7 @@ static void of_pwmchip_add(struct pwm_chip *chip)
 
 static void of_pwmchip_remove(struct pwm_chip *chip)
 {
-	if (chip->dev && chip->dev->of_node)
+	if (chip->dev)
 		of_node_put(chip->dev->of_node);
 }