If v4l2_ctrl_handler_setup() fails then probe() should return an error
code instead of returning success.

Fixes: cee1e3e2 ("media: add video control handlers using V4L2 control framework")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YBKFkbATXa5fA3xj@mwandaSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>