vhost-user-input: use free(elem) instead of g_free(elem)

The virtqueue element returned by vu_queue_pop() is allocated using
malloc(3) by virtqueue_alloc_element().  Use the matching free(3)
function instead of glib's g_free().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20191119111626.112206-1-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

contrib/vhost-user-input/main.c

@@ -77,7 +77,7 @@ static void vi_input_send(VuInput *vi, struct virtio_input_event *event)
         len = iov_from_buf(elem->in_sg, elem->in_num,
                            0, &vi->queue[i].event, sizeof(virtio_input_event));
         vu_queue_push(dev, vq, elem, len);
-        g_free(elem);
+        free(elem);
     }
 
     vu_queue_notify(&vi->dev.parent, vq);
@@ -153,7 +153,7 @@ static void vi_handle_sts(VuDev *dev, int qidx)
                          0, &event, sizeof(event));
         vi_handle_status(vi, &event);
         vu_queue_push(dev, vq, elem, len);
-        g_free(elem);
+        free(elem);
     }
 
     vu_queue_notify(&vi->dev.parent, vq);