mt76: mt7915: check for devm_pinctrl_get() failure

If devm_pinctrl_get() fails then it leads to an error pointer
dereference.  Add a check to prevent that.

Fixes: 99ad32a4 ("mt76: mt7915: add support for MT7986")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/soc.c

@@ -196,6 +196,8 @@ static int mt7986_wmac_gpio_setup(struct mt7915_dev *dev)
 
 	type = mt7986_wmac_check_adie_type(dev);
 	pinctrl = devm_pinctrl_get(dev->mt76.dev);
+	if (IS_ERR(pinctrl))
+		return PTR_ERR(pinctrl);
 
 	switch (type) {
 	case ADIE_SB: