libcamera: FrameBuffer: Add a setRequest() interface

Add the ability to set the Request a buffer is associated with. This is
needed for buffers that live inside a pipeline handler and is
temporarily associated with a request as it's being processed inside the
pipeline.

While we are at it delete a stray semicolon.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

include/libcamera/buffer.h

@@ -52,7 +52,8 @@ public:
 	const std::vector<Plane> &planes() const { return planes_; }
 
 	Request *request() const { return request_; }
-	const FrameMetadata &metadata() const { return metadata_; };
+	void setRequest(Request *request) { request_ = request; }
+	const FrameMetadata &metadata() const { return metadata_; }
 
 	unsigned int cookie() const { return cookie_; }
 	void setCookie(unsigned int cookie) { cookie_ = cookie; }