Check for inactive controls in uvc_ctrl_is_accessible().

Use the new value for the master_id controls if present, otherwise
use the existing value to determine if it is OK to set the control.
Doing this here avoids attempting to set an inactive control, which
will return an error from the USB device, which returns an invalid
errorcode.

This fixes:
  warn: v4l2-test-controls.cpp(483): s_ctrl returned EIO
  warn: v4l2-test-controls.cpp(483): s_ctrl returned EIO
test VIDIOC_G/S_CTRL: OK
  warn: v4l2-test-controls.cpp(739): s_ext_ctrls returned EIO
  warn: v4l2-test-controls.cpp(739): s_ext_ctrls returned EIO
  warn: v4l2-test-controls.cpp(816): s_ext_ctrls returned EIO
test VIDIOC_G/S/TRY_EXT_CTRLS: OK

Tested with:
v4l2-ctl -c auto_exposure=1
OK
v4l2-ctl -c exposure_time_absolute=251
OK
v4l2-ctl -c auto_exposure=3
OK
v4l2-ctl -c exposure_time_absolute=251
VIDIOC_S_EXT_CTRLS: failed: Input/output error
exposure_time_absolute: Input/output error
ERROR
v4l2-ctl -c auto_exposure=3,exposure_time_absolute=251,auto_exposure=1
v4l2-ctl -C auto_exposure,exposure_time_absolute  
auto_exposure: 1
exposure_time_absolute: 251
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>