[media] tea575x: allow multiple opens

Change locking to allow tea575x-radio device to be opened multiple times.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/sound/tea575x-tuner.h b/include/sound/tea575x-tuner.h
index 5aa8186..726e947 100644
--- a/include/sound/tea575x-tuner.h
+++ b/include/sound/tea575x-tuner.h
@@ -49,7 +49,7 @@
 	bool tuned;			/* tuned to a station */
 	unsigned int val;		/* hw value */
 	unsigned long freq;		/* frequency */
-	unsigned long in_use;		/* set if the device is in use */
+	struct mutex mutex;
 	struct snd_tea575x_ops *ops;
 	void *private_data;
 	u8 card[32];