pinctrl: sunxi: Fix potential null pointer dereference

kzalloc can fail. Add a null check to avoid null pointer
dereference error while accessing the pointer later.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sunxi/pinctrl-sunxi.c

@@ -211,6 +211,10 @@ static int sunxi_pctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 			configlen++;
 
 		pinconfig = kzalloc(configlen * sizeof(*pinconfig), GFP_KERNEL);
+		if (!pinconfig) {
+			kfree(*map);
+			return -ENOMEM;
+		}
 
 		if (!of_property_read_u32(node, "allwinner,drive", &val)) {
 			u16 strength = (val + 1) * 10;