libcamera: v4l2_subdevice: Close subdevice when destroyed

Make sure the subdevice file descriptor isn't leaked by closing it when
the V4L2Subdevice instance is destroyed.

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

src/libcamera/include/v4l2_subdevice.h

@@ -35,6 +35,7 @@ public:
 	explicit V4L2Subdevice(const MediaEntity *entity);
 	V4L2Subdevice(const V4L2Subdevice &) = delete;
 	V4L2Subdevice &operator=(const V4L2Subdevice &) = delete;
+	~V4L2Subdevice();
 
 	int open();
 	bool isOpen() const;

src/libcamera/v4l2_subdevice.cpp

@@ -112,6 +112,11 @@ V4L2Subdevice::V4L2Subdevice(const MediaEntity *entity)
 {
 }
 
+V4L2Subdevice::~V4L2Subdevice()
+{
+	close();
+}
+
 /**
  * \brief Open a V4L2 subdevice
  *