gpio: max732x: use guard(mutex) to simplify locking

Convert the max732x driver to use the RAII-based guard(mutex) macro from
<linux/cleanup.h>. This change replaces manual mutex_lock() and
mutex_unlock() calls, allowing the chip lock to be managed automatically
based on function scope.

Refactor max732x_gpio_set_mask() and max732x_irq_update_mask() to
improve code readability. This allows for direct returns and removes
the redundant 'out' label in the set_mask function, resulting in
cleaner and more maintainable code.

While at it: order includes alphabetically and add missing ones.

Signed-off-by: Richard Lyu <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
[Bartosz: tweak commit message, add err.h and device.h to includes]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpio-max732x.c

···
  *  Derived from drivers/gpio/pca953x.c
  */
 
-#include <linux/module.h>
+#include <linux/cleanup.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_data/max732x.h>
 #include <linux/slab.h>
 #include <linux/string.h>
-#include <linux/gpio/driver.h>
-#include <linux/interrupt.h>
-#include <linux/i2c.h>
-#include <linux/platform_data/max732x.h>
 
 /*
  * Each port of MAX732x (including MAX7319) falls into one of the
···
 	uint8_t reg_out;
 	int ret;
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
 
 	reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
 	reg_out = (reg_out & ~mask) | (val & mask);
 
 	ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
 	if (ret < 0)
-		goto out;
+		return;
 
 	/* update the shadow register then */
 	if (off > 7)
 		chip->reg_out[1] = reg_out;
 	else
 		chip->reg_out[0] = reg_out;
-out:
-	mutex_unlock(&chip->lock);
 }
 
 static int max732x_gpio_set_value(struct gpio_chip *gc, unsigned int off,
···
 	if (chip->irq_features == INT_NO_MASK)
 		return;
 
-	mutex_lock(&chip->lock);
+	guard(mutex)(&chip->lock);
 
 	switch (chip->irq_features) {
 	case INT_INDEP_MASK:
···
 		max732x_writeb(chip, 1, (uint8_t)msg);
 		break;
 	}
-
-	mutex_unlock(&chip->lock);
 }
 
 static void max732x_irq_mask(struct irq_data *d)