gpio: cdev: Fix resource leaks on errors in lineinfo_changed_notify()

On error handling paths, lineinfo_changed_notify() doesn't free the
allocated resources which results leaks.  Fix it.

Cc: stable@vger.kernel.org
Fixes: d4cd090 ("gpio: cdev: make sure the cdev fd is still active before emitting events")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20260120030857.2144847-1-tzungbi@kernel.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Author: Tzung-Bi Shih

drivers/gpio/gpiolib-cdev.c

@@ -2549,6 +2549,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
 	ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
 	if (!ctx) {
 		pr_err("Failed to allocate memory for line info notification\n");
+		fput(fp);
 		return NOTIFY_DONE;
 	}