mfd: ene-kb3930: Fix a potential NULL pointer dereference

The off_gpios could be NULL. Add missing check in the kb3930_probe().
This is similar to the issue fixed in commit b1ba8bc
("backlight: hx8357: Fix potential NULL pointer dereference").

This was detected by our static analysis tool.

Cc: stable@vger.kernel.org
Fixes: ede6b2d ("mfd: ene-kb3930: Add driver for ENE KB3930 Embedded Controller")
Suggested-by: Lee Jones <lee@kernel.org>
Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
Link: https://lore.kernel.org/r/20250224233736.1919739-1-chenyuan0y@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: WhiteFox-Project

drivers/mfd/ene-kb3930.c

@@ -162,7 +162,7 @@ static int kb3930_probe(struct i2c_client *client)
 			devm_gpiod_get_array_optional(dev, "off", GPIOD_IN);
 		if (IS_ERR(ddata->off_gpios))
 			return PTR_ERR(ddata->off_gpios);
-		if (ddata->off_gpios->ndescs < 2) {
+		if (ddata->off_gpios && ddata->off_gpios->ndescs < 2) {
 			dev_err(dev, "invalid off-gpios property\n");
 			return -EINVAL;
 		}