gpio: pisosr: Use devm_mutex_init()

Use devm_mutex_init() instead of hand-writing it.

This saves some LoC, improves readability and saves some space in the
generated .o file.

Before:
======
   text	   data	    bss	    dec	    hex	filename
   8431	   1808	    192	  10431	   28bf	drivers/gpio/gpio-pisosr.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   8112	   1736	    192	  10040	   2738	drivers/gpio/gpio-pisosr.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/01910ebdaba7d8d0cdc4ac60eb70da8e29cb85f1.1757251512.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: tititiou36

drivers/gpio/gpio-pisosr.c

@@ -108,11 +108,6 @@ static const struct gpio_chip template_chip = {
 	.can_sleep		= true,
 };
 
-static void pisosr_mutex_destroy(void *lock)
-{
-	mutex_destroy(lock);
-}
-
 static int pisosr_gpio_probe(struct spi_device *spi)
 {
 	struct device *dev = &spi->dev;
@@ -139,8 +134,7 @@ static int pisosr_gpio_probe(struct spi_device *spi)
 		return dev_err_probe(dev, PTR_ERR(gpio->load_gpio),
 				     "Unable to allocate load GPIO\n");
 
-	mutex_init(&gpio->lock);
-	ret = devm_add_action_or_reset(dev, pisosr_mutex_destroy, &gpio->lock);
+	ret = devm_mutex_init(dev, &gpio->lock);
 	if (ret)
 		return ret;