[media] media: v4l2-pci-skeleton: Fix error handling path in 'skeleton_probe()'

If this memory allocation fails, we must release some resources, as
already done in the code below and above.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

samples/v4l/v4l2-pci-skeleton.c

@@ -772,8 +772,10 @@ static int skeleton_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	/* Allocate a new instance */
 	skel = devm_kzalloc(&pdev->dev, sizeof(struct skeleton), GFP_KERNEL);
-	if (!skel)
-		return -ENOMEM;
+	if (!skel) {
+		ret = -ENOMEM;
+		goto disable_pci;
+	}
 
 	/* Allocate the interrupt */
 	ret = devm_request_irq(&pdev->dev, pdev->irq,