We recently added locking to this function, but there was an error path
which accidentally returned holding a lock.  Also we returned zero on
failure on some paths instead of the error code.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
        v4l2_ctrl_new_custom(hdl, &m2mtest_ctrl_trans_time_msec, NULL);
        v4l2_ctrl_new_custom(hdl, &m2mtest_ctrl_trans_num_bufs, NULL);
        if (hdl->error) {
-               int err = hdl->error;
-
+               rc = hdl->error;
                v4l2_ctrl_handler_free(hdl);
-               return err;
+               goto open_unlock;
        }
        ctx->fh.ctrl_handler = hdl;
        v4l2_ctrl_handler_setup(hdl);
 
 open_unlock:
        mutex_unlock(&dev->dev_mutex);
-       return 0;
+       return rc;
 }
 
 static int m2mtest_release(struct file *file)