vdev: remove unused fileds from file_t

src/drivers/device/vdev.h

@@ -61,14 +61,12 @@ namespace device __EXPORT
 {
 
 struct file_t {
-	int fd;
 	int flags;
-	mode_t mode;
 	void *priv;
 	void *vdev;
 
-	file_t() : fd(-1), flags(0), priv(NULL), vdev(NULL) {}
-	file_t(int f, void *c, int d) : fd(d), flags(f), priv(NULL), vdev(c) {}
+	file_t() : flags(0), priv(NULL), vdev(NULL) {}
+	file_t(int f, void *c) : flags(f), priv(NULL), vdev(c) {}
 };
 
 /**

src/drivers/device/vdev_posix.cpp

@@ -155,8 +155,8 @@ extern "C" {
 			return -1;
 		}
 
-		PX4_DEBUG("px4_open fd = %d", filemap[i]->fd);
-		return filemap[i]->fd;
+		PX4_DEBUG("px4_open fd = %d", i);
+		return i;
 	}
 
 	int px4_close(int fd)