media: em28xx: Fix possible memory leak of em28xx struct

The em28xx struct kref isn't being decreased after an error in the
em28xx_ir_init, leading to a possible memory leak.

A kref_put and em28xx_shutdown_buttons is added to the error handler code.
Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/usb/em28xx/em28xx-input.c

@@ -720,7 +720,8 @@ static int em28xx_ir_init(struct em28xx *dev)
 			dev->board.has_ir_i2c = 0;
 			dev_warn(&dev->intf->dev,
 				 "No i2c IR remote control device found.\n");
-			return -ENODEV;
+			err = -ENODEV;
+			goto ref_put;
 		}
 	}
 
@@ -735,7 +736,7 @@ static int em28xx_ir_init(struct em28xx *dev)
 
 	ir = kzalloc(sizeof(*ir), GFP_KERNEL);
 	if (!ir)
-		return -ENOMEM;
+		goto ref_put;
 	rc = rc_allocate_device(RC_DRIVER_SCANCODE);
 	if (!rc)
 		goto error;
@@ -839,6 +840,9 @@ static int em28xx_ir_init(struct em28xx *dev)
 	dev->ir = NULL;
 	rc_free_device(rc);
 	kfree(ir);
+ref_put:
+	em28xx_shutdown_buttons(dev);
+	kref_put(&dev->ref, em28xx_free_device);
 	return err;
 }