[media] Docbook: fix comments at v4l2-flash-led-class.h

Warning(.//include/media/v4l2-flash-led-class.h:51): bad line: 				unique in the system
Warning(.//include/media/v4l2-flash-led-class.h:56): bad line: 				definitions are available in the header file
Warning(.//include/media/v4l2-flash-led-class.h:57): bad line: 				<linux/led-class-flash.h>
Warning(.//include/media/v4l2-flash-led-class.h:122): No description found for parameter 'ops'
Warning(.//include/media/v4l2-flash-led-class.h:122): Excess function parameter 'flash_ops' description in 'v4l2_flash_init'
Warning(.//include/media/v4l2-flash-led-class.h:130): No description found for parameter 'v4l2_flash'
Warning(.//include/media/v4l2-flash-led-class.h:130): Excess function parameter 'flash' description in 'v4l2_flash_release'

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>