staging: cx25821: avoid NULL pointer dereference

Assign dev only if fh is not NULL.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/cx25821/cx25821-audups11.c

@@ -343,10 +343,11 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
 			 struct v4l2_control *ctl)
 {
 	struct cx25821_fh *fh = priv;
-	struct cx25821_dev *dev = fh->dev;
+	struct cx25821_dev *dev;
 	int err;
 
 	if (fh) {
+		dev = fh->dev;
 		err = v4l2_prio_check(&dev->prio, &fh->prio);
 		if (0 != err)
 			return err;

drivers/staging/cx25821/cx25821-video.c

@@ -963,10 +963,11 @@ int cx25821_set_freq(struct cx25821_dev *dev, struct v4l2_frequency *f)
 int vidioc_s_frequency(struct file *file, void *priv, struct v4l2_frequency *f)
 {
 	struct cx25821_fh *fh = priv;
-	struct cx25821_dev *dev = fh->dev;
+	struct cx25821_dev *dev;
 	int err;
 
 	if (fh) {
+		dev = fh->dev;
 		err = v4l2_prio_check(&dev->prio, &fh->prio);
 		if (0 != err)
 			return err;