[media] marvell-cam: Remove broken "owner" logic

The marvell cam driver retained just enough of the owner-tracking logic
from cafe_ccic to be broken; it could, conceivably, cause the driver to
release DMA memory while the controller is still active.  Simply remove the
remaining pieces and ensure that the controller is stopped before we free
things.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/marvell-ccic/mcam-core.c

@@ -1564,11 +1564,8 @@ static int mcam_v4l_release(struct file *filp)
 			singles, delivered);
 	mutex_lock(&cam->s_mutex);
 	(cam->users)--;
-	if (filp == cam->owner) {
-		mcam_ctlr_stop_dma(cam);
-		cam->owner = NULL;
-	}
 	if (cam->users == 0) {
+		mcam_ctlr_stop_dma(cam);
 		mcam_cleanup_vb2(cam);
 		mcam_ctlr_power_down(cam);
 		if (cam->buffer_mode == B_vmalloc && alloc_bufs_at_read)

drivers/media/video/marvell-ccic/mcam-core.h

@@ -107,7 +107,6 @@ struct mcam_camera {
 	enum mcam_state state;
 	unsigned long flags;		/* Buffer status, mainly (dev_lock) */
 	int users;			/* How many open FDs */
-	struct file *owner;		/* Who has data access (v4l2) */
 
 	/*
 	 * Subsystem structures.