[media] s5p-fimc: Fix locking in subdev set_crop op

When setting TRY crop on the sub-device the mutex was erroneously acquired
rather than released on exit path. This bug is present in kernels starting
from v3.2.

Cc: stable@vger.kernel.org
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/s5p-fimc/fimc-capture.c

@@ -1383,7 +1383,7 @@ static int fimc_subdev_set_crop(struct v4l2_subdev *sd,
 	fimc_capture_try_crop(ctx, r, crop->pad);
 
 	if (crop->which == V4L2_SUBDEV_FORMAT_TRY) {
-		mutex_lock(&fimc->lock);
+		mutex_unlock(&fimc->lock);
 		*v4l2_subdev_get_try_crop(fh, crop->pad) = *r;
 		return 0;
 	}