gpio: pca953x: Move memcpy into mutex lock for set multiple

Need to ensure that reg_output is not updated while setting multiple
bits. This makes the mutex locking behaviour for the set_multiple call
consistent with that of the set_value call.

Cc: stable@vger.kernel.org
Fixes: b4818afeac ("gpio: pca953x: Add set_multiple to allow multiple")
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-pca953x.c

@@ -372,8 +372,8 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 
 	bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
 
-	memcpy(reg_val, chip->reg_output, NBANK(chip));
 	mutex_lock(&chip->i2c_lock);
+	memcpy(reg_val, chip->reg_output, NBANK(chip));
 	for (bank = 0; bank < NBANK(chip); bank++) {
 		bank_mask = mask[bank / sizeof(*mask)] >>
 			   ((bank % sizeof(*mask)) * 8);
@@ -608,7 +608,6 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
 
 	if (client->irq && irq_base != -1
 			&& (chip->driver_data & PCA_INT)) {
-
 		ret = pca953x_read_regs(chip,
 					chip->regs->input, chip->irq_stat);
 		if (ret)