gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()

Commit 709d71a1 ("gpio: mpc8xxx: use gpiochip data pointer") replaces
the use of container_of() with gpiochip_get_data(). However, the data
pointer is not yet set by the time the save_regs function is called.

Fixes: 709d71a1 ("gpio: mpc8xxx: use gpiochip data pointer")
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mpc8xxx.c

@@ -51,7 +51,8 @@ static inline u32 mpc8xxx_gpio2mask(unsigned int gpio)
 
 static void mpc8xxx_gpio_save_regs(struct of_mm_gpio_chip *mm)
 {
-	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(&mm->gc);
+	struct mpc8xxx_gpio_chip *mpc8xxx_gc =
+		container_of(mm, struct mpc8xxx_gpio_chip, mm_gc);
 
 	mpc8xxx_gc->data = in_be32(mm->regs + GPIO_DAT);
 }