media: media/pci: prevent memory leak in bttv_probe

In bttv_probe if some functions such as pci_enable_device,
pci_set_dma_mask and request_mem_region fails the allocated
 memory for btv should be released.
Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/pci/bt8xx/bttv-driver.c

@@ -4013,11 +4013,13 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
 	btv->id  = dev->device;
 	if (pci_enable_device(dev)) {
 		pr_warn("%d: Can't enable device\n", btv->c.nr);
-		return -EIO;
+		result = -EIO;
+		goto free_mem;
 	}
 	if (pci_set_dma_mask(dev, DMA_BIT_MASK(32))) {
 		pr_warn("%d: No suitable DMA available\n", btv->c.nr);
-		return -EIO;
+		result = -EIO;
+		goto free_mem;
 	}
 	if (!request_mem_region(pci_resource_start(dev,0),
 				pci_resource_len(dev,0),
@@ -4025,7 +4027,8 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
 		pr_warn("%d: can't request iomem (0x%llx)\n",
 			btv->c.nr,
 			(unsigned long long)pci_resource_start(dev, 0));
-		return -EBUSY;
+		result = -EBUSY;
+		goto free_mem;
 	}
 	pci_set_master(dev);
 	pci_set_command(dev);
@@ -4211,6 +4214,10 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
 	release_mem_region(pci_resource_start(btv->c.pci,0),
 			   pci_resource_len(btv->c.pci,0));
 	pci_disable_device(btv->c.pci);
+
+free_mem:
+	bttvs[btv->c.nr] = NULL;
+	kfree(btv);
 	return result;
 }