libcamera: v4l2_subdevice: Return a unique pointer from fromEntityName()

The fromEntityName() function returns a pointer to a newly allocated
V4L2Subdevice 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_path.cpp

@@ -24,14 +24,13 @@ RkISP1Path::RkISP1Path(const char *name, const Span<const PixelFormat> &formats,
 		       const Size &minResolution, const Size &maxResolution)
 	: name_(name), running_(false), formats_(formats),
 	  minResolution_(minResolution), maxResolution_(maxResolution),
-	  resizer_(nullptr), video_(nullptr), link_(nullptr)
+	  video_(nullptr), link_(nullptr)
 {
 }
 
 RkISP1Path::~RkISP1Path()
 {
 	delete video_;
-	delete resizer_;
 }
 
 bool RkISP1Path::init(MediaDevice *media)