V4L/DVB (12112): cx231xx: fix uninitialized variable.

The variable 'rc' could be used uninitialized in the cx231xx_capture_start
function. Sri informed me that it should be initialized to -1.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx231xx/cx231xx-avcore.c

@@ -2055,7 +2055,7 @@ int cx231xx_initialize_stream_xfer(struct cx231xx *dev, u32 media_type)
 
 int cx231xx_capture_start(struct cx231xx *dev, int start, u8 media_type)
 {
-	int rc;
+	int rc = -1;
 	u32 ep_mask = -1;
 	struct pcb_config *pcb_config;