libcamera: v4l2_videodevice: Pass FileDescriptor to open()

The V4L2VideoDevice::open() function that takes an open file handle
duplicates it internally, and leaves the original handle untouched. This
is documented but not enforced through language constructs. Fix it by
passing a FileDescriptor to the function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/internal/v4l2_videodevice.h

@@ -184,7 +184,7 @@ public:
 	~V4L2VideoDevice();
 
 	int open();
-	int open(int handle, enum v4l2_buf_type type);
+	int open(FileDescriptor handle, enum v4l2_buf_type type);
 	void close();
 
 	const char *driverName() const { return caps_.driver(); }