pinctrl: nuvoton: check for devm_kasprintf() failure

devm_kasprintf() may return NULL on failure of internal allocation thus
the assignment to  .label  is not safe if not checked. On error
npcm7xx_gpio_of() returns negative values so -ENOMEM in the
(unlikely) failure case of devm_kasprintf() should be fine here.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: 3b588e43 ("pinctrl: nuvoton: add NPCM7xx pinctrl and GPIO driver")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c

@@ -1925,6 +1925,9 @@ static int npcm7xx_gpio_of(struct npcm7xx_pinctrl *pctrl)
 			pctrl->gpio_bank[id].gc.label =
 				devm_kasprintf(pctrl->dev, GFP_KERNEL, "%pOF",
 					       np);
+			if (pctrl->gpio_bank[id].gc.label == NULL)
+				return -ENOMEM;
+
 			pctrl->gpio_bank[id].gc.dbg_show = npcmgpio_dbg_show;
 			pctrl->gpio_bank[id].direction_input =
 				pctrl->gpio_bank[id].gc.direction_input;