commit 8c279e93 upstream.

When parsing the UVC control descriptors fails, the error path tries to
cleanup a media device that hasn't been initialised, potentially
resulting in a crash. Fix this by initialising the media device before
the error handling path can be reached.

Fixes: 5a254d75 ("[media] uvcvideo: Register a v4l2_device")
Reported-by:  <syzbot+c86454eb3af9e8a4da20@syzkaller.appspotmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>