Remove the verbose #ifndef/#define/#endif pattern for maintaining
header idempotency, and replace it with a simple #pragma once.
This simplifies the headers, and prevents redundant changes when
header files get moved.
The internal/request.h was missed at the time of the original
conversion. Update it.
Fixes: df131ad088 ("libcamera: internal: Convert to pragma once")
Tested-by: Ashok Sidipotu <ashok.sidipotu@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>