pinctrl: abx500: Fix checking if pin use AlternateFunction register

It's pointless to check "af.alt_bit1 == UNUSED" twice.
This looks like a copy-paste bug, I think what we want is to check if *both*
af.alt_bit1 and af.alt_bit2 are UNUSED.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-abx500.c

@@ -422,7 +422,7 @@ static u8 abx500_get_mode(struct pinctrl_dev *pctldev, struct gpio_chip *chip,
 	}
 
 	/* check if pin use AlternateFunction register */
-	if ((af.alt_bit1 == UNUSED) && (af.alt_bit1 == UNUSED))
+	if ((af.alt_bit1 == UNUSED) && (af.alt_bit2 == UNUSED))
 		return mode;
 	/*
 	 * if pin GPIOSEL bit is set and pin supports alternate function,