media: v4l2-ctrls: show all owned controls in log_status

VIDIOC_LOG_STATUS will log the controls owned by the driver. But the
code didn't take into account the case where a single driver creates
multiple control handlers. A good example is the vivid driver, but
others use it as well.

Modify v4l2_ctrl_handler_log_status() so that it really shows all
controls owned by this driver.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>