pinctrl: sunplus: Add check for kcalloc

As the potential failure of the kcalloc(),
it should be better to check it in order to
avoid the dereference of the NULL pointer.

Fixes: aa74c44 ("pinctrl: Add driver for Sunplus SP7021")
Reported-by: Hacash Robot <hacashRobot@santino.com>
Signed-off-by: William Dean <williamsukatube@gmail.com>
Link: https://lore.kernel.org/r/20220710154822.2610801-1-williamsukatube@163.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: William Dean

drivers/pinctrl/sunplus/sppctl.c

@@ -871,6 +871,9 @@ static int sppctl_dt_node_to_map(struct pinctrl_dev *pctldev, struct device_node
 	}
 
 	*map = kcalloc(*num_maps + nmG, sizeof(**map), GFP_KERNEL);
+	if (*map == NULL)
+		return -ENOMEM;
+
 	for (i = 0; i < (*num_maps); i++) {
 		dt_pin = be32_to_cpu(list[i]);
 		pin_num = FIELD_GET(GENMASK(31, 24), dt_pin);