[media] drivers/media/video/tlg2300/pd-video.c: Remove second mutex_unlock in pd_vidioc_s_fmt

Error path in file drivers/media/video/tlg2300/pd-video.c:
1. First mutex_unlock on &pd->lock in line 767 (in function that
   called from line 805)
2. Second in line  806

 805        pd_vidioc_s_fmt(pd, &f->fmt.pix);
 806        mutex_unlock(&pd->lock);

Found by Linux Device Drivers Verification Project
Signed-off-by: Alexander Strakh <strakh@ispras.ru>
Acked-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/tlg2300/pd-video.c

@@ -764,10 +764,8 @@ static int pd_vidioc_s_fmt(struct poseidon *pd, struct v4l2_pix_format *pix)
 	}
 	ret |= send_set_req(pd, VIDEO_ROSOLU_SEL,
 				vid_resol, &cmd_status);
-	if (ret || cmd_status) {
-		mutex_unlock(&pd->lock);
+	if (ret || cmd_status)
 		return -EBUSY;
-	}
 
 	pix_def->pixelformat = pix->pixelformat; /* save it */
 	pix->height = (context->tvnormid & V4L2_STD_525_60) ?  480 : 576;