pinctrl: axp209: Fix NULL pointer dereference after allocation

axp20x_build_funcs_groups allocates groups via devm_kcalloc and tries to
dereference without checking for NULL. This patch avoids such a
scenario.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-axp209.c

@@ -366,6 +366,8 @@ static int axp20x_build_funcs_groups(struct platform_device *pdev)
 		pctl->funcs[i].groups = devm_kcalloc(&pdev->dev,
 						     npins, sizeof(char *),
 						     GFP_KERNEL);
+		if (!pctl->funcs[i].groups)
+			return -ENOMEM;
 		for (pin = 0; pin < npins; pin++)
 			pctl->funcs[i].groups[pin] = pctl->desc->pins[pin].name;
 	}