staging: bcm2835-camera: handle wait_for_completion_timeout return properly

wait_for_completion_timeout returns unsigned long not int so a variable of
proper type is introduced. Further the check for <= 0 is ambiguous and
should be == 0 here indicating timeout.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: 7b3ad5ab ("staging: Import the BCM2835 MMAL-based V4L2 camera driver.")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c

@@ -580,6 +580,7 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 static void stop_streaming(struct vb2_queue *vq)
 {
 	int ret;
+	unsigned long timeout;
 	struct bm2835_mmal_dev *dev = vb2_get_drv_priv(vq);
 
 	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev, "%s: dev:%p\n",
@@ -605,10 +606,10 @@ static void stop_streaming(struct vb2_queue *vq)
 				      sizeof(dev->capture.frame_count));
 
 	/* wait for last frame to complete */
-	ret = wait_for_completion_timeout(&dev->capture.frame_cmplt, HZ);
-	if (ret <= 0)
+	timeout = wait_for_completion_timeout(&dev->capture.frame_cmplt, HZ);
+	if (timeout == 0)
 		v4l2_err(&dev->v4l2_dev,
-			 "error %d waiting for frame completion\n", ret);
+			 "timed out waiting for frame completion\n");
 
 	v4l2_dbg(1, bcm2835_v4l2_debug, &dev->v4l2_dev,
 		 "disabling connection\n");