V4L: Int if: Set slave's master before attach, remove master argument

Set slave's master before master's attach call.

The master also now gets its own pointer from slave's structure.
Signed-off-by: Sakari Ailus <sakari.ailus@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/media/video/v4l2-int-device.c

@@ -57,12 +57,12 @@ static void v4l2_int_device_try_attach_all(void)
 			if (!try_module_get(m->module))
 				continue;
 
-			if (m->u.master->attach(m, s)) {
+			s->u.slave->master = m;
+			if (m->u.master->attach(s)) {
+				s->u.slave->master = NULL;
 				module_put(m->module);
 				continue;
 			}
-
-			s->u.slave->master = m;
 		}
 	}
 }

include/media/v4l2-int-device.h

@@ -44,9 +44,8 @@ enum v4l2_int_type {
 struct v4l2_int_device;
 
 struct v4l2_int_master {
-	int (*attach)(struct v4l2_int_device *master,
-		      struct v4l2_int_device *slave);
-	void (*detach)(struct v4l2_int_device *master);
+	int (*attach)(struct v4l2_int_device *slave);
+	void (*detach)(struct v4l2_int_device *slave);
 };
 
 typedef int (v4l2_int_ioctl_func)(struct v4l2_int_device *);