[media] mceusb: fix usbdev leak

mceusb_init_rc_dev() does usb_get_dev(), but there is no any
usb_put_dev() in the driver.

The patch tries to straighten logic. It moves usb_get_dev()
directly to mceusb_dev_probe() and adds usb_put_dev() to an error path
and to mceusb_dev_disconnect().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/rc/mceusb.c

@@ -1202,10 +1202,9 @@ static void mceusb_flash_led(struct mceusb_dev *ir)
 	mce_async_out(ir, FLASH_LED, sizeof(FLASH_LED));
 }
 
-static struct rc_dev *mceusb_init_rc_dev(struct mceusb_dev *ir,
-					 struct usb_interface *intf)
+static struct rc_dev *mceusb_init_rc_dev(struct mceusb_dev *ir)
 {
-	struct usb_device *udev = usb_get_dev(interface_to_usbdev(intf));
+	struct usb_device *udev = ir->usbdev;
 	struct device *dev = ir->dev;
 	struct rc_dev *rc;
 	int ret;
@@ -1345,7 +1344,7 @@ static int mceusb_dev_probe(struct usb_interface *intf,
 	if (!ir->urb_in)
 		goto urb_in_alloc_fail;
 
-	ir->usbdev = dev;
+	ir->usbdev = usb_get_dev(dev);
 	ir->dev = &intf->dev;
 	ir->len_in = maxp;
 	ir->flags.microsoft_gen1 = is_microsoft_gen1;
@@ -1366,7 +1365,7 @@ static int mceusb_dev_probe(struct usb_interface *intf,
 		snprintf(name + strlen(name), sizeof(name) - strlen(name),
 			 " %s", buf);
 
-	ir->rc = mceusb_init_rc_dev(ir, intf);
+	ir->rc = mceusb_init_rc_dev(ir);
 	if (!ir->rc)
 		goto rc_dev_fail;
 
@@ -1412,6 +1411,7 @@ static int mceusb_dev_probe(struct usb_interface *intf,
 
 	/* Error-handling path */
 rc_dev_fail:
+	usb_put_dev(ir->usbdev);
 	usb_free_urb(ir->urb_in);
 urb_in_alloc_fail:
 	usb_free_coherent(dev, maxp, ir->buf_in, ir->dma_in);
@@ -1439,6 +1439,7 @@ static void mceusb_dev_disconnect(struct usb_interface *intf)
 	usb_kill_urb(ir->urb_in);
 	usb_free_urb(ir->urb_in);
 	usb_free_coherent(dev, ir->len_in, ir->buf_in, ir->dma_in);
+	usb_put_dev(dev);
 
 	kfree(ir);
 }