pinctrl: sunxi: Fix a memory leak in 'sunxi_pinctrl_build_state()'

If 'krealloc()' fails, 'pctl->functions' is set to NULL.
We should instead use a temp variable in order to be able to free the
previously allocated memeory, in case of OOM.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sunxi/pinctrl-sunxi.c

@@ -1042,6 +1042,7 @@ static int sunxi_pinctrl_add_function(struct sunxi_pinctrl *pctl,
 static int sunxi_pinctrl_build_state(struct platform_device *pdev)
 {
 	struct sunxi_pinctrl *pctl = platform_get_drvdata(pdev);
+	void *ptr;
 	int i;
 
 	/*
@@ -1108,13 +1109,15 @@ static int sunxi_pinctrl_build_state(struct platform_device *pdev)
 	}
 
 	/* And now allocated and fill the array for real */
-	pctl->functions = krealloc(pctl->functions,
-				   pctl->nfunctions * sizeof(*pctl->functions),
-				   GFP_KERNEL);
-	if (!pctl->functions) {
+	ptr = krealloc(pctl->functions,
+		       pctl->nfunctions * sizeof(*pctl->functions),
+		       GFP_KERNEL);
+	if (!ptr) {
 		kfree(pctl->functions);
+		pctl->functions = NULL;
 		return -ENOMEM;
 	}
+	pctl->functions = ptr;
 
 	for (i = 0; i < pctl->desc->npins; i++) {
 		const struct sunxi_desc_pin *pin = pctl->desc->pins + i;