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

commit 386377b5 upstream.

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.

Fixes: b4818afe ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpio/gpio-pca953x.c

@@ -372,8 +372,8 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
 		break;
 	}
 
-	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++) {
 		unsigned bankmask = mask[bank / sizeof(*mask)] >>
 				    ((bank % sizeof(*mask)) * 8);