media: v4l2-compat-ioctl32.c: make ctrl_is_pointer work for subdevs

BugLink: http://bugs.launchpad.net/bugs/1756121

commit 273caa26 upstream.

If the device is of type VFL_TYPE_SUBDEV then vdev->ioctl_ops
is NULL so the 'if (!ops->vidioc_query_ext_ctrl)' check would crash.
Add a test for !ops to the condition.

All sub-devices that have controls will use the control framework,
so they do not have an equivalent to ops->vidioc_query_ext_ctrl.
Returning false if ops is NULL is the correct thing to do here.

Fixes: b8c601e8 ("v4l2-compat-ioctl32.c: fix ctrl_is_pointer")
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/media/v4l2-core/v4l2-compat-ioctl32.c

@@ -612,7 +612,7 @@ static inline bool ctrl_is_pointer(struct file *file, u32 id)
 		return ctrl && ctrl->is_ptr;
 	}
 
-	if (!ops->vidioc_query_ext_ctrl)
+	if (!ops || !ops->vidioc_query_ext_ctrl)
 		return false;
 
 	return !ops->vidioc_query_ext_ctrl(file, fh, &qec) &&