libcamera: v4l2_device: Return a unique pointer from fromEntityName()

The fromEntityName() function returns a pointer to a newly allocated
V4L2Device instance, which must be deleted by the caller. This opens the
door to memory leaks. Return a unique pointer instead, which conveys the
API semantics better than a sentence in the documentation.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

src/libcamera/pipeline/rkisp1/rkisp1.cpp

@@ -178,7 +178,6 @@ class PipelineHandlerRkISP1 : public PipelineHandler
 {
 public:
 	PipelineHandlerRkISP1(CameraManager *manager);
-	~PipelineHandlerRkISP1();
 
 	CameraConfiguration *generateConfiguration(Camera *camera,
 		const StreamRoles &roles) override;
@@ -218,8 +217,8 @@ private:
 
 	MediaDevice *media_;
 	std::unique_ptr<V4L2Subdevice> isp_;
-	V4L2VideoDevice *param_;
-	V4L2VideoDevice *stat_;
+	std::unique_ptr<V4L2VideoDevice> param_;
+	std::unique_ptr<V4L2VideoDevice> stat_;
 
 	RkISP1MainPath mainPath_;
 	RkISP1SelfPath selfPath_;
@@ -599,16 +598,10 @@ CameraConfiguration::Status RkISP1CameraConfiguration::validate()
 }
 
 PipelineHandlerRkISP1::PipelineHandlerRkISP1(CameraManager *manager)
-	: PipelineHandler(manager), param_(nullptr), stat_(nullptr)
+	: PipelineHandler(manager)
 {
 }
 
-PipelineHandlerRkISP1::~PipelineHandlerRkISP1()
-{
-	delete param_;
-	delete stat_;
-}
-
 /* -----------------------------------------------------------------------------
  * Pipeline Operations
  */